It has been almost a year and a half since Turkey asked Germany to investigate reports on the whereabouts of Adil Öksüz, a key Gülenist Terror Group (FETÖ) figure in the July 15 coup attempt.

The German authorities, however, have maintained their silence. The request has followed multiple reports of sightings of Öksüz in Germany, a favorite destination for FETÖ members. German Interior Ministry's first response was that there was a detention warrant for Öksüz dating back to January 2018. It was also confirmed by Chancellor Angela Merkel. Investigations in Turkey concluded that Öksüz fled abroad after he was controversially released by a Turkish court following his initial capture immediately after the coup attempt. Turkish expatriates in Germany reported multiple sightings of Öksüz and media reports said Öksüz has applied for asylum in Germany.

Turkey formally requested information but when the European country did not respond, Ankara sent an extradition request. Turkey followed up the case and repeatedly asked for a progress report on the case but Germany did not respond.

Originally a theology lecturer, Adil Öksüz had a more sinister profession according to Turkish authorities. As an "imam" or point man for FETÖ, he planned the putsch attempt with the terrorist group's infiltrators in the military. He is currently on the Interior Ministry's Most Wanted list, with a reward of TL 4 million for tips leading to his capture. Öksüz was first detained just outside Akıncı Air Base, a military base in the capital Ankara after the coup attempt was foiled. The base was sort of a command center for the putschists with warplanes taking off from there striking strategic locations. However, hours after his detention, a court controversially ordered his release with judicial control. Öksüz was last seen in Sakarya, the northwestern city where he taught at a university, before his disappearance. Months of manhunts across Turkey failed to yield results and authorities concluded that he fled abroad.

Referred to as FETÖ's "black box" for his intricate ties to senior cadres and prominent role in the coup attempt, Öksüz reportedly acted as the Air Force leader for the terrorist group. FETÖ leader Fetullah Gülen and Öksüz are being tried in absentia in several coup cases. Both men face multiple life sentences for their suspected role in the coup attempt that came three years after FETÖ members in the judiciary and law enforcement tried two other unsuccessful coup attempts.

Hakan Bıyık, a colonel who confessed his ties to the terrorist group, had revealed Öksüz's role in the coup attempt in his testimony and detailed how Öksüz and military officers in the "Peace At Home Council" plotted the insurrection bid in a villa in Ankara.

Adil Öksüz told interrogators that he was near Akıncı base to "check out a piece of land he was planning to purchase," just like Kemal Batmaz, his alleged co-conspirator in the putsch attempt, when he was captured. Batmaz, currently in jail on coup charges, was a former executive of a FETÖ-run company and was among other "civilian" FETÖ members captured at or near the airbase. "Öksüz told us that Gülen instructed the generals, FETÖ's infiltrators in the military, to convince [Chief of the General Staff] Hulusi Akar to join the coup," Bıyık told a court during a hearing in the trial of 227 defendants involved in the coup attempt. According to Bıyık, Gülen told Öksüz that "[Hulusi Akar] would be put into retirement this summer." Indeed, several generals were expected to be retired by a supreme military council overseeing the army's appointments in August 2016. "We discussed everything from how to kidnap President Erdoğan from his Istanbul residence and then taking him to a military ship, to the kidnapping of the prime minister and interior minister using Special Forces as well as the kidnapping of the intelligence chief," Hakan Bıyık told the court. "Failure was not an option. When we talked about what we would do if the plans were unsuccessful, Öksüz told us not to think the worst," Bıyık said.

Following the coup attempt, nearly 500 FETÖ members, from soldiers to judges and prosecutors fled to Germany, seeking asylum. FETÖ, which runs a global network of members, has its largest network in Europe in Germany. It runs a large number of associations, companies and websites in the country. Following the coup attempt that killed 251 people, FETÖ members kept a low-profile while their private schools, a main source of revenue for the group, faced a financial bottleneck as more Turks withdrew their children from the schools. The group is known for offering financial assistance to its members arriving in Germany seeking asylum.