Yasir Kaya, a speaker and the former news director of Fenerbahçe football club’s TV channel was taken under custody over his alleged use of ByLock mobile app, on Friday.

Earlier, Istanbul Public Prosecutor’s Office issued detention warrants for 35 journalists including Kaya.

Turkish authorities believe using ByLock is a sign of being a member of the Gülen movement, which the government accuses of masterminding a failed coup attempt on July 15, 2016. The mobile phone application ByLock is considered as the top communication tool among members of the group.

Istanbul police, on Friday, detained Kaya who has joined other 10 colleagues under police custody as part of the same investigation: Birgün daily newspaper’s editor Burak Ekici, Vatan newspaper’s page editor Yusuf Duran; Ihlas news agency’s former news chief Ömer Faruk Aydemir; former Türkiye daily columnist Ahmet Sağırlı, former Zaman reporter Muhsin Pilgir; former Cihan news agency reporter Sait Gürkan Tuzlu; former Samanyolu TV news editor Cüneyt Seza Özkan; former Cihan news agency reporter Mutlu Özay and Ahmet Feyzullah Özyurt.

Police have yet to locate the remaining 24 journalists.