Detention warrants were issued for 55 former employees of the now-closed publisher, Isik Yayincilik, media reported.
An Istanbul prosecutor ordered detentions for 55 suspects scattered across 13 provinces, state-run Anadolu said Friday.
Isik Yayincilik was known for publishing books by Fethullah Gulen until it was shut down as part of a post-coup government decree.
Turkish government blames the Gulen movement for the July 15, 2016 failed coup while the latter denies involvement.
More than 150,000 people have passed through police custody and 60,000 of them were put in pretrial detention.