Şık was transferred to police headquarters ahead of his referral to court.
Şık also confirmed his detention on his Twitter account.
“I am being detained. I will be taken to the prosecutor’s office regarding a tweet,” he tweeted.
Şık and journalist Nedim Şener were jailed as part of the controversial Oda TV case in 2011. Both journalists spent more than a year in prison while awaiting trial before the publication of Şık’s book, titled “The Imam’s Army,” which focused on the organization of U.S.-based Islamic preacher Fethullah Gülen’s followers within the police and the judiciary during the time when the movement and the ruling Justice and Development Party (AKP) were close. The duo were eventually freed on March 12, 2012.
The Gülen movement has been accused of perpetrating the July 15 failed coup attempt.