Turkish police carried out simultaneous raids targeting alleged members of Gülen movement on the morning of 29 September 2026 in İstanbul, İzmir, Kocaeli, Gaziantep, Kayseri and Kırıkkale. Twenty people were detained. The operation was conducted by the Anti-Smuggling and Organised Crime Branch of the İstanbul Police Directorate.

Of those detained, five are serving public employees, working in health, education and other public institutions. Four are public employees previously dismissed, from education. Eleven work in the private sector.

According to the police account, the grounds are that statement from a secret witness in the investigation; that they were in contact with members of the organisation; that Bank Asya account movements were identified; that payphone and consecutive-call records were identified; and that they were active at a responsible level within the organisation.

Bank Asya was placed under the administration of the state deposit insurance fund in May 2015 and its banking licence was revoked in July 2016. Any account movement relied on is therefore at least ten years old.

In Yüksel Yalçınkaya v. Türkiye in September 2023, the Grand Chamber of the European Court of Human Rights examined the use of this category of material in Gülen-related prosecutions. It held that criminal liability may not be attached in a virtually automatic manner without establishing that all the elements of the offence of membership of an armed terrorist organisation, including the requisite intent, had been met, and it identified a systemic problem requiring general measures. It reached the same conclusion on the assessment of intent in Yasak v. Türkiye in May 2026.

A report published in July 2026 by Johan Vande Lanotte, emeritus professor at Ghent University, recorded that in operations carried out during 2025, Turkish authorities continued to rely on Bank Asya deposits and on frequent use of payphone cards, alongside statements by collaborating witnesses. He noted that both Bank Asya accounts and the earlier ByLock evidence concern facts more than a decade old.

Turkish Justice Ministry figures released in July 2026 record 127,102 convictions for alleged links to the movement since 2016, with 83,404 cases pending.

BoldMedya, which reported the operation, described the investigation as unlawful. The authorities have released no further detail on the secret witness or on what the suspects are said to have done.

Ten years after the coup attempt, twenty people were detained on the strength of bank records from a bank that no longer exists, telephone records, and the statement of a witness whose identity is withheld.