Turkish authorities have seized 10 companies owned by Ankara-based defense contractor Assan Group and detained two of its senior executives as part of an expanding military espionage investigation, the state-run Anadolu news agency reported.
The İstanbul Chief Public Prosecutor’s Office said Wednesday that company owner Emin Öner and general manager Gürcan Okumuş were taken into custody over alleged ties to the faith-based Gülen movement, which Ankara designates as a terrorist organization but which is not recognized as such internationally, and on suspicion of espionage. The prosecutor’s statement did not give any details about how the detained suspects were involved in military espionage.
Turkey’s Savings Deposit Insurance Fund (TMSF) was appointed as trustee to oversee the seized companies, all operating under Assan Group Makine Savunma Sanayi A.Ş., prosecutors said.
The investigation also led to the arrest of İsmet Sayhan, former chairman of the board of the state-run Mechanical and Chemical Industry Corporation (MKE). Sayhan was jailed on Wednesday on charges of unlawfully obtaining and misusing documents related to state security, after reports in the Turkish press alleged he leaked Turkish Armed Forces (TSK) procurement plans to the Assan Group.
The Assan Group denied the accusations in a written statement released on Tuesday, calling them part of a “baseless smear campaign.”
The company said the documents cited in the case were not military secrets but internal files outlining its 2025–27 production and delivery schedules, prepared at the request of the Turkish Land Forces Command. It said the files remain in its official records.
The detention of Sayhan, who is described in the Turkish media as close to Nationalist Movement Party (MHP) leader Devlet Bahçeli, and the operation against the Assan Group also come just days after the detention and subsequent arrest of Selahattin Yılmaz, a convicted mob boss long associated with nationalist circles. Yılmaz and nine others were jailed last week in the same case, which prosecutors say involves an armed crime organization active across five provinces.
MKE, the company Sayhan once led, is a key weapons producer that manufactures ammunition, artillery and other materiel for the TSK. It is widely seen as a strategic pillar of the country’s defense industry, making the arrest of a former chairman particularly sensitive.
Assan Group’s history and business operations
Founded in 1985, the Assan Group operates in the defense, health and construction equipment sectors. The company also runs a shooting range for firearms testing.
In February it showcased ammunition, rockets and bombs compatible with both NATO and Russian standards at the IDEX 2025 defense exhibition in Abu Dhabi. The Assan Group says it exports to more than 60 countries across six continents and serves over 200 clients.
Okumuş, the company’s detained general manager, previously headed the Defense Industry Research and Development Institute (SAGE) of Turkey’s Scientific and Technological Research Council (TÜBİTAK) between 2018 and 2024.
Prosecutors said the investigation is “continuing on multiple fronts.”
The Turkish government has seized hundreds of companies over their alleged links to the Gülen movement since a failed coup in July 2016, which it blamed on the movement.
According to figures published by the Anadolu news agency last month on the coup’s ninth anniversary, the government has seized 784 companies with a total asset value of TL 42.3 billion at the time of their takeover, an estimated $14 billion in 2016 USD terms, as part of a sweeping crackdown on the Gülen movement that followed the abortive putsch.
Over the last decade Turkish-Islamic scholar Fethullah Gülen and his movement, which in the past had been praised by the Turkish government for their activities in education and interreligious and intercultural dialogue, have faced various accusations from the government, including masterminding corruption investigations in 2013 and a coup attempt in July 2016.
Gülen had been living in the United States since 1999 and passed away at a hospital in Pennsylvania on October 20 at the age of 83.
The Turkish government labeled Gülen and his movement as “terrorists” in May 2016.
Gülen and his followers have strongly denied any involvement in the coup or any terrorist activity but have been the subject of a harsh crackdown for a decade, which intensified in the aftermath of the abortive putsch.
While the Turkish government claims it is pursuing a legitimate national security threat, critics argue that the seizures and mass detentions have served as a means of political repression, wiping out an entire civil and business ecosystem associated with the movement.
Rights groups have described the actions as collective punishment, while some former officials and commentators have used terms like “genocide” in reference to the scale and intensity of the crackdown.