Messages sent by fugitive former prosecutor Zekeriya Öz through the encrypted messaging app ByLock has been given as confirmation of his ties to the Gülenist Terror Group (FETÖ). Öz was behind a string of high-profile trials that later turned out to be sham trials he and others masterminded to imprison critics of FETÖ.

In the messages published in the Akşam newspaper, Öz discusses his "dreams" and "dreams friends experienced" with a fellow FETÖ member. Dreams constitute an important place in esoteric rhetoric Fethullah Gülen uses to captivate his followers. "The prophet was leading us and Hocaefendi was right next to him. We were marching to a place during Judgment Day," Öz says as he explains a dream a FETÖ member had. Hocaefendi is the Turkish name given to Gülen by his followers.

In another message, Öz instructs a fellow FETÖ-linked prosecutor "not to surrender" as the police stepped up a crackdown on the terrorist group. A message sent to Öz by a FETÖ member tells him he was "forgotten" by public which is "good".

Öz was one of the prosecutors behind two disguised coup attempts in 2013 by FETÖ. He fled abroad last year after authorities issued arrest warrants for him and two other prosecutors for links to FETÖ. Öz never publicly acknowledged links to FETÖ, although his close ties to Gülenists are known, including relations with fellow FETÖ-linked prosecutors and judges. He faces a life sentence for crimes committed on behalf of the terrorist group.

Öz, a media-savvy figure, rose to fame as the prosecutor who conducted the Ergenekon investigation in 2007. Ergenekon, according to Öz's indictment, was a terrorist organization formed by former generals, journalists, academics, dignitaries and many others bent on fomenting chaos in Turkey. Years later, it was discovered that Öz and other prosecutors on the case forged evidence to imprison the defendants, most of whom are staunch critics of Gülenists. The defendants in the Ergenekon trial were acquitted after new prosecutors exposed the plot to imprison them.

An investigation by authorities launched in early 2016 discovered that ByLock was exclusively used by FETÖ for correspondence, ranging from coup plans to sharing Gülen's statements. The ByLock investigation was expanded after last summer's coup attempt and thousands of people whoever used the messaging app have been detained or arrested.