Suspects, Evidence and Assets Abroad: International Judicial Cooperation in Turkish Capital Markets Criminal Cases under Law No. 6706 — Mutual Legal Assistance, Extradition, Transfer of Proceedings and Fugitive Suspects

Market manipulation on Borsa Istanbul is an offence committed in Turkey even when the orders are placed from abroad. The Criminal Code treats an act as committed in Turkey if it is carried out partly in Turkey or its result occurs here (Art. 8(1)). When suspects, evidence or proceeds of crime are abroad, Turkish prosecutors work through Law No. 6706 on International Judicial Cooperation in Criminal Matters (Official Gazette 5 May 2016, No. 29703) and the Council of Europe conventions Türkiye has ratified. Under Law No. 6706, the Ministry of Justice is the central authority (Art. 2(b)). Prosecutors may ask foreign states to preserve evidence before a formal request is sent (Art. 7(1)(a)). Seizure in Turkey at a foreign state’s request is possible only for extraditable offences (Art. 8(1)(ç)). Information obtained through cooperation may be used without the sending state’s permission in civil cases connected with the offence (Art. 6(2)(c)). Turkish citizens are not extradited, except for obligations to the International Criminal Court (Constitution Art. 38). Assets in Turkey belonging to fugitive suspects may be seized to compel their return, for listed offences that include qualified fraud and criminal organisation (Criminal Procedure Code Art. 248). This guide explains these rules for foreign institutions that are victims in the 2026 cases. It reflects the legislation in force as at 26 October 2026.

Why the cross-border rules matter in the 2026 cases

Capital markets offences rarely stay within one country. Orders may be placed through foreign accounts or from abroad, proceeds may be moved to foreign banks within days, and suspects may leave Turkey before an investigation becomes public. Foreign institutions that suffered losses may themselves hold evidence abroad, such as trading records, communications with intermediaries and internal analyses.

Four questions follow. Can Turkey prosecute conduct partly carried out abroad? How do Turkish prosecutors obtain evidence and freeze assets abroad? What happens when a suspect is outside Turkey? And what can a foreign victim do, both in the criminal file and in its civil claims? The answers are in the Criminal Code’s jurisdiction rules, Law No. 6706, the Criminal Procedure Code’s provisions on absent and fugitive suspects, and the international conventions to which Türkiye is a party.

The legal framework

Law No. 6706 on International Judicial Cooperation in Criminal Matters sets the procedures for judicial cooperation in criminal matters with foreign states (Art. 1). Its separate parts deal with mutual legal assistance, extradition, transfer of proceedings, transfer of enforcement and transfer of sentenced persons. International agreements on judicial cooperation to which Türkiye is a party, and other statutory provisions, are reserved (Art. 1(3)). Where Law No. 6706 and other laws are silent, the Criminal Procedure Code No. 5271 applies (Art. 5).

The Constitution provides that, except for obligations arising from being party to the International Criminal Court, a citizen may not be extradited to a foreign country on account of an offence (Art. 38, last paragraph). It also prohibits general confiscation (Art. 38). The Criminal Code No. 5237 sets the territorial and extraterritorial reach of Turkish criminal law (Arts. 8–13) and the rules on confiscation (Arts. 54–55). The Criminal Procedure Code governs seizure (Art. 128), the victim’s rights (Art. 234), and absent and fugitive suspects (Arts. 244–248).

Türkiye is a party to the main Council of Europe conventions in criminal matters. According to the Ministry of Justice’s list, they entered into force for Türkiye on the dates in the table below.

Turkish jurisdiction over cross-border conduct

Turkish law applies to offences committed in Turkey. An offence is regarded as committed in Turkey if the act is carried out wholly or partly in Turkey, or if its result occurs in Turkey (Criminal Code Art. 8(1)). Orders entered from abroad into Borsa Istanbul’s trading system, or false information spread from abroad to influence the prices of Turkish capital market instruments, therefore fall within Turkish jurisdiction where the act or its result takes place in Turkey. A person convicted abroad of an offence committed in Turkey is tried again in Turkey (Art. 9).

For offences committed wholly abroad, the Criminal Code applies narrower rules. A Turkish citizen who commits abroad an offence carrying a minimum penalty of at least one year’s imprisonment is punished under Turkish law if he or she is in Turkey, has not been tried abroad for it and the offence can be prosecuted in Turkey (Art. 11(1)). A foreigner who commits such an offence abroad to the detriment of a Turkish citizen or a legal person established under Turkish law, and who is in Turkey, is punished on the victim’s complaint if not already tried abroad (Art. 12(2)). Where the victim is a foreigner, prosecution requires the Minister of Justice’s request and further conditions, including that the offence carries a minimum penalty of at least three years and that there is no extradition treaty or that extradition has been refused (Art. 12(3)).

The Capital Markets Law’s market manipulation offences carry three to five years’ imprisonment and a judicial fine (Capital Markets Law Art. 107(1)–(2)). That is well above the one-year threshold that Law No. 6706 uses for extradition and transfer of proceedings. The general offences often charged alongside them, such as qualified fraud and forming an organisation to commit crime, are explained in our guide on Criminal Code offences.

The central authority and general principles

The Ministry of Justice is the central authority (Law No. 6706 Art. 2(b)). It decides, under the treaties to which Türkiye is a party or on the basis of reciprocity, whether to accept foreign requests and whether Turkish judicial authorities’ requests are appropriate. It also decides the type of cooperation and the method to be followed, and it consents to, limits or attaches conditions to the use of information and documents requested by states (Art. 3(1)). Where there is no legal and practical reciprocity, it may require the requesting state to guarantee that it will meet Turkish requests of the same kind (Art. 3(2)). Conditions it accepts and guarantees it gives bind the judicial authorities, except in matters within judicial jurisdiction (Art. 3(4)). It may refuse a request where the work and cost involved would be clearly out of proportion to the seriousness of the offence (Art. 3(6)).

Foreign requests may be refused where they would violate Turkey’s sovereignty, national security, public order or other fundamental interests. They may also be refused where the offence is purely military, an offence of thought or a political offence, where there are substantial grounds to believe the person would be persecuted or ill-treated for discriminatory reasons, or where the requesting state lacks basic guarantees of the right of defence (Art. 4).

Use of information (speciality). Information and documents received through cooperation may not be used, without the sending state’s permission, outside the investigation, prosecution or enforcement for which they were requested (Art. 6(1)). No permission is needed where the legal characterisation of the offence changes, where new suspects or accused who emerge later are brought into the proceedings, or where the information and documents are needed in civil cases connected with the offence (Art. 6(2)).

Turkish requests for evidence abroad

Courts, judges and prosecutors may request mutual legal assistance on matters needed to conclude an investigation or prosecution or to enforce a conviction (Law No. 6706 Art. 7(1)). The Law provides for the following:

• ▸ Urgent preservation. Where delay would be harmful, provisional measures to preserve evidence may be requested before the formal request is sent (Art. 7(1)(a)).
• ▸ Service abroad. Requests for service of documents may not contain warnings that restrictive or coercive measures will be applied (Art. 7(1)(b)).
• ▸ Presence. Turkish authorities may ask to be present when the requested act is carried out (Art. 7(1)(c)).
• ▸ Validity. Acts carried out by the requested state under its own law are valid under Turkish law (Art. 7(1)(ç)).
• ▸ Spontaneous information. Information learned in a Turkish investigation that could lead another state to open a criminal investigation may be passed to the central authority for transmission without any request (Art. 7(2)).
• ▸ Video and audio links. Assistance may be requested by video and audio link. It is conducted under the direction and law of the requested state, or, where a treaty provides, under Turkish direction and law (Art. 9(1)–(2)).

For a foreign victim, the practical point is timing. Evidence abroad, such as bank records, account opening documents or electronic data, is easier to preserve than to recover later. The Cybercrime Convention provides mechanisms for preserving stored computer data. The Mutual Assistance Convention and its protocols govern letters rogatory, and a request for urgent provisional measures under Art. 7(1)(a) can be made before the full request is prepared.

Foreign requests executed in Turkey

Requests from foreign judicial authorities are carried out under Turkish law. A special procedure requested by the foreign state may be followed if it does not conflict with Turkish law (Law No. 6706 Art. 8(1)(a)). Turkish authorities may refuse a request in whole or in part, or ask for more information (Art. 8(1)(b)). Where delay would be harmful, provisional measures to preserve evidence may be taken before the request arrives. If the request does not reach the central authority within forty days, the measure is lifted at once (Art. 8(1)(c)).

A request for search or seizure may be carried out only if the offence concerned is one for which extradition is possible. For assets, immovable property, rights and receivables seized on such a request, the Turkish authorities ask the requesting state at least once a year whether the measure should continue (Art. 8(1)(ç)). Requests for service that contain warnings of coercive measures are refused (Art. 8(1)(d)). Foreign authorities may ask to be present when the act is carried out (Art. 8(1)(e)). A request may be refused where a Turkish court has already convicted or acquitted the person of the same act, or the offence is covered by an amnesty or time-barred (Art. 8(1)(f)). Where a foreign state asks for assistance by video link under a treaty, the act is carried out under the foreign authority’s direction and law, in the presence of Turkish judicial authorities, who ensure that fundamental principles of Turkish law are not breached (Art. 9(3)).

Extradition from and to Turkey

Extradition from Turkey. A foreigner under investigation, prosecution or conviction for an offence committed abroad may be extradited on request (Law No. 6706 Art. 10(1)). The offence must carry a maximum of at least one year’s imprisonment under both the requesting state’s law and Turkish law; for final convictions, the sentence imposed must be at least four months (Art. 10(2)). The person may then be tried or punished only for the offences on which extradition was granted (Art. 10(4)).

Extradition is refused where the person is a Turkish citizen (subject to International Criminal Court obligations), or where there are strong grounds for suspicion of persecution or ill-treatment. It is also refused where the offence is political, purely military, committed against the security of the Turkish State or to the detriment of Turkey, a Turkish citizen or a legal person established under Turkish law, or falls within Turkish jurisdiction. Other grounds are that the offence is time-barred or covered by an amnesty, that the person has already been convicted or acquitted in Turkey for the act, or that the offence carries the death penalty or a punishment incompatible with human dignity (Art. 11(1)). For capital markets cases, this means that a foreign suspect found in Turkey will normally be tried in Turkey rather than extradited, because conduct on Borsa Istanbul falls within Turkish jurisdiction.

The procedure runs through the central authority’s review (Art. 13), the high criminal court where the person is found, or in Ankara if the location is unknown (Art. 15), and an appeal to the Court of Cassation, which decides within three months (Art. 18(4)). The court’s decision is implemented on the Minister of Justice’s proposal and the President’s approval, after the opinions of the Ministries of Foreign Affairs and the Interior (Art. 19(1)). Provisional arrest may be ordered before the request arrives. The person must be brought before a judge within twenty-four hours, and under reciprocity may be held for no more than forty days (Art. 14(3)–(4)). Detention pending extradition is reviewed at intervals of no more than thirty days (Art. 16(2)). Objects useful as evidence, or obtained through the offence and found on the person or later, may be handed over to the requesting state, but not those belonging to third parties in good faith (Art. 20(4)–(6)).

Extradition to Turkey. Turkish judicial authorities may request the extradition of a person abroad for whom an arrest warrant or detention order has been issued, to complete an investigation or prosecution or to enforce a conviction (Art. 22(1)). The offence must carry a maximum of at least one year’s imprisonment, or, for final convictions, a sentence of at least four months (Art. 22(2)). The central authority may decline to send a request that does not meet the conditions, that is clearly disproportionate, or that could harm national security or international relations (Art. 22(3)). Whether a foreign state grants the request depends on its own law and the treaties between the two states; many states, like Turkey, do not extradite their own nationals.

Transfer of proceedings and enforcement

Under Law No. 6706 and the treaties, investigations and prosecutions in Turkey may be transferred to foreign states, and those in foreign states may be taken over. Without a treaty, reciprocity applies (Art. 23). Turkish proceedings for offences carrying a maximum of at least one year may be transferred in two cases. The first is where a foreign suspect cannot be brought before the Turkish authorities and his or her statement cannot be taken through mutual assistance. The second is where a Turkish suspect habitually resides in the foreign state, or the evidence is there, so that transfer would help establish the truth (Art. 24(1)). The request does not stop the Turkish proceedings (Art. 24(2)). If it is accepted, an investigation is postponed and ends with a decision not to prosecute once the foreign authority files charges; a prosecution is stayed and ends once the foreign court convicts. If the foreign authority does not act effectively, the Turkish proceedings continue (Art. 24(3)–(5)). Where delay would be harmful, the requested state may be asked to take all provisional measures, including seizure and arrest, together with or before the transfer request (Art. 24(6)).

Turkey may take over a foreign investigation or prosecution for an offence committed abroad carrying a maximum of at least one year. The request is refused if the person is not habitually resident in Turkey, is not a Turkish citizen, the offence was committed outside the requesting state, or the person has already been tried in Turkey for the act (Art. 25(1)). Investigative acts and evidence obtained under the requesting state’s law are valid under Turkish law (Art. 25(3)).

Foreign convictions may be enforced in Turkey if the convicted person is in Turkey, the judgment is final, the act is an offence under Turkish law and not time-barred, and, for custodial sentences, at least six months remain to be served (Art. 26(1)). The Ankara high criminal court adapts the sentence to Turkish law within fifteen days, without exceeding the foreign sentence (Art. 26(5)). Turkish convictions may be transferred for enforcement abroad on similar conditions (Art. 28).

Absent and fugitive suspects

An accused whose whereabouts are unknown, or who is abroad and cannot be brought before the competent court or whose appearance is not considered appropriate, is treated as absent (gaip). No hearing is opened against an absent accused, but the court takes the steps needed to obtain or preserve evidence (Criminal Procedure Code Art. 244(1)–(2)). The court may issue a safe conduct promising that the accused will not be detained if he or she appears, subject to conditions (Art. 246).

A person who hides in Turkey or stays abroad to frustrate the investigation or prosecution, and who therefore cannot be reached, is a fugitive (kaçak) (Art. 247(1)). For the offences listed in Art. 248(2), the suspect is summoned by newspaper announcement and a notice posted at the last known home, with a warning that the measures in Art. 248 may follow. A suspect who does not come forward within fifteen days is declared a fugitive (Art. 247(2)). Following the amendment made by Law No. 7589, in force since 31 July 2026, a fugitive accused may be prosecuted. If he or she has not previously been questioned, however, the court may not convict or decide that no penalty should be imposed, and where a security measure is ordered the accused or defence counsel may ask for a retrial in order to exercise the right of defence (Art. 247(3)). The court appoints a lawyer from the bar where there is a hearing and no defence counsel (Art. 247(4)).

To make a fugitive come forward or appear at trial, the fugitive’s property, rights and receivables in Turkey may be seized, in proportion to that aim, by decision of a criminal judge of peace on the prosecutor’s request, or by the court. A trustee may be appointed to manage them (Art. 248(1)). The rule applies to offences listed in Art. 248(2). The list includes, among others, abuse of trust (Criminal Code Art. 155), fraud and qualified fraud (Arts. 157 and 158), fraudulent bankruptcy (Art. 161), forming an organisation to commit crime (Art. 220) and embezzlement under the Banking Law. The Capital Markets Law offences are not in the list. Seizure under Art. 248 is therefore available in capital markets cases only where one of the listed offences is also under investigation or prosecution. The seizure is lifted when the fugitive is caught or surrenders (Art. 248(4)). A detention order may be issued in the fugitive’s absence (Art. 248(5)), and the decisions may be challenged by objection (Art. 248(8)).

Proceeds of crime abroad

Turkish law confiscates the material benefits obtained through an offence, forming its subject or provided for its commission, and the economic gains from investing or converting them. It does so only where the benefit cannot be returned to the victim (Criminal Code Art. 55(1)). Where the benefits cannot be seized, their equivalent value is confiscated (Art. 55(2)). General confiscation of a person’s entire property is prohibited (Constitution Art. 38). Within Turkey, seizure of assets during the investigation follows Criminal Procedure Code Art. 128, explained in our guide on freezing assets.

For assets abroad, a Turkish seizure or confiscation order has no direct effect; it must be executed by the foreign state. Turkish prosecutors and courts request provisional measures and, after judgment, execution of confiscation through Law No. 6706 and the treaties, in particular the 1990 Strasbourg Convention on laundering and confiscation (ETS 141) and the 2005 Warsaw Convention (CETS 198). Where delay would be harmful, provisional measures may be requested before the formal request (Law No. 6706 Art. 7(1)(a)) or together with a transfer of proceedings (Art. 24(6)). Whether the foreign state freezes, confiscates or returns assets, and whether victims there have priority, depends on its law and the applicable treaty.

Conversely, assets in Turkey may be seized at a foreign state’s request only for extraditable offences, with an annual check on whether the measure should continue (Art. 8(1)(ç)).

Financial intelligence and regulator cooperation

Alongside judicial cooperation, two administrative channels operate. The Financial Crimes Investigation Board (MASAK) exchanges information with foreign counterpart units, and providing information to them under the anti-money laundering law is not a breach of secrecy (Law No. 5549 Art. 22(3)). The Minister may also suspend a transaction, or refuse to let it proceed, for seven working days on a reasoned request from a foreign counterpart unit, on the basis of reciprocity, where MASAK also sees a suspicion of laundering or terrorist financing (Art. 19/A(2)).

The Capital Markets Board may sign bilateral or multilateral memoranda of understanding with equivalent foreign authorities. These cover exchanging information, meeting document requests, inspecting the Turkish offices, branches or affiliates of firms active in foreign capital markets, and taking administrative measures (Capital Markets Law Art. 128(1)(d)). These channels serve regulatory and financial intelligence purposes; evidence for criminal trials is obtained through judicial cooperation.

The foreign victim’s role

A foreign institution that has suffered loss is a victim (suçtan zarar gören) and may file a complaint. During the investigation, the victim and the complainant may ask for evidence to be collected and, without harming the confidentiality and purpose of the investigation, ask the prosecutor for copies of documents. Through a lawyer, they may examine the investigation documents and seized items under Art. 153, and object to a decision not to prosecute (Criminal Procedure Code Art. 234(1)(a)). During the prosecution, they may be notified of the hearing, join the public prosecution as a participating party, ask for copies of records and documents, and ask for witnesses to be summoned (Art. 234(1)(b)). These rights are explained in our guide on joining a criminal case.

In cross-border cases, three uses of these rights matter. First, the victim may ask the prosecutor to seek evidence or provisional measures abroad, identifying where records and assets are likely to be found. Second, the victim may submit evidence it holds abroad directly, with the authentication and translation the Turkish authorities require. Third, through file access it may obtain documents that arrived through cooperation and use them in connected civil cases without further permission from the sending state (Law No. 6706 Art. 6(2)(c)).

Points for foreign institutional investors

1. 1. Register as a victim early. A complaint and a request to be treated as a victim give access to the rights in Criminal Procedure Code Art. 234, including the right to ask for evidence to be collected.
2. 2. Map the foreign footprint. Identify where accounts, intermediaries, servers and persons involved are located, so that requests can be targeted at the right states.
3. 3. Ask for urgent preservation. Provisional measures may be requested before the formal request (Law No. 6706 Art. 7(1)(a)); evidence and money move fast.
4. 4. Prepare own evidence for use in Turkey. Trading records, confirmations and correspondence held abroad can be submitted directly, with authentication and sworn translation.
5. 5. Follow assets in Turkey too. For listed offences, a fugitive’s property in Turkey may be seized under Criminal Procedure Code Art. 248; seizure under Art. 128 applies more generally.
6. 6. Insist on restitution first. Proceeds are confiscated only if they cannot be returned to the victim (Criminal Code Art. 55(1)).
7. 7. Use cooperation evidence in civil claims. Documents received from abroad may be used in connected civil cases (Law No. 6706 Art. 6(2)(c)).
8. 8. Coordinate with home-state authorities. Turkish authorities may pass information spontaneously to other states (Art. 7(2)), and a complaint in the investor’s home state may lead that state to send its own request to Turkey.
9. 9. Expect Turkish trials for Turkish suspects. Turkish citizens are not extradited (Constitution Art. 38), so suspects who return or are found in Turkey are tried here.
10. 10. Watch limitation periods. Civil claims run on their own deadlines whatever the pace of cross-border criminal cooperation.

Time limits and thresholds

Frequently asked questions

Can Turkey prosecute market manipulation carried out from abroad?

Yes, where the act is partly carried out in Turkey or its result occurs in Turkey, the offence is treated as committed in Turkey (Criminal Code Art. 8(1)).

Who handles international cooperation requests in Turkey?

The Ministry of Justice, as central authority (Law No. 6706 Arts. 2(b) and 3).

Can evidence obtained from abroad be used in a civil damages claim?

Yes, where it is needed in civil cases connected with the offence; the sending state’s permission is not required (Law No. 6706 Art. 6(2)(c)).

Can a Turkish prosecutor ask a foreign state to freeze evidence urgently?

Yes. Provisional measures to preserve evidence may be requested before the formal request where delay would be harmful (Law No. 6706 Art. 7(1)(a)).

Does Turkey extradite its own citizens?

No, except for obligations arising from being a party to the International Criminal Court (Constitution Art. 38; Law No. 6706 Art. 11(1)(a)).

Will Turkey extradite a foreign suspect for conduct on Borsa Istanbul?

Normally not, because offences within Turkish jurisdiction or committed to the detriment of Turkish persons are grounds for refusal (Law No. 6706 Art. 11(1)(c)); the suspect is tried in Turkey.

What is the threshold for extradition?

A maximum penalty of at least one year’s imprisonment, or a final sentence of at least four months (Law No. 6706 Arts. 10(2) and 22(2)).

Can assets in Turkey be seized at a foreign state’s request?

Yes, but only for extraditable offences, and the requesting state is asked at least annually whether the measure should continue (Law No. 6706 Art. 8(1)(ç)).

What happens to a suspect who flees abroad?

He or she may be declared a fugitive, prosecuted subject to limits, detained in absence, and, for listed offences, have property in Turkey seized (Criminal Procedure Code Arts. 247–248).

Are Capital Markets Law offences in the list for seizing fugitives’ assets?

No. The list in Criminal Procedure Code Art. 248(2) includes qualified fraud and criminal organisation but not the Capital Markets Law offences.

Are proceeds of crime returned to victims or confiscated?

Confiscation applies only where the benefit cannot be returned to the victim (Criminal Code Art. 55(1)).

Which conventions govern confiscation across borders?

Mainly the Strasbourg Convention (ETS 141), in force for Türkiye since 1 February 2005, and the Warsaw Convention (CETS 198), together with Law No. 6706.

Can MASAK cooperate with a foreign financial intelligence unit?

Yes. Information given to foreign counterparts is not a breach of secrecy (Law No. 5549 Art. 22(3)), and transactions may be suspended on a foreign unit’s reasoned request (Art. 19/A(2)).

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