Istanbul Chief Prosecutor's Office has issued detention warrants for 24 suspects following an investigation into a 2012 plot by the Gülenist Terror Group (FETÖ) to implicate Hakan Fidan, the head of the Turkish intelligence service, in wrongdoing.

Fidan, undersecretary of National Intelligence Directorate (MİT), and some other officials from the agency were summoned by an Istanbul prosecutor on Feb. 7, 2012, to testify in a probe related to the PKK terrorist group.

However, Fidan and the other suspects involved in the case did not cooperate with the prosecutor, after being instructed by then-Prime Minister and current President Recep Tayyip Erdoğan.

It was later revealed to be a plot to implicate Fidan with trumped-up terror charges and a criminal investigation found it was the work of FETÖ's infiltrators in the judiciary to remove Fidan from MİT, one of few places the terrorist group failed to secure a large number of infiltrators in the army, the judiciary and police.

Detention warrants were issued for FETÖ leader Fetullah Gülen, the group's point man Murat Karabulut, former police chiefs - some of who are already jailed in other FETÖ cases - as well as Sadrettin Sarıkaya and Bilal Bayraktar, prosecutors who tried to issue an arrest warrant for Fidan.

Gülen and four others in the case remain at large while six were detained in nationwide operations yesterday.