ANKARA, Jan. 4 (Xinhua) -- A delegation of U.S. officials on Thursday attended the interrogation of key suspects and witnesses of the 2016 coup attempt for their preliminary inquiry on foundations linked to Gulen movement in the U.S.
The U.S. delegation, which is paying a two-day visit to Ankara, is the second delegation in Turkey having talks with the Turkish authorities, Anadolu Agency reported on Friday.
The visiting delegation included the Washington Prosecutor, U.S. Attorney for the Eastern District of New York, a U.S. Justice Department official, a FBI official and an IT specialist, accompanied by embassy officials.
The interrogation request was made by Washington about one and a half month ago for the three people and the questions were sent by the U.S. authorities within the scope of their own investigations on Gulen movement.
The U.S. and Turkish officials held a meeting and the former presented some information on judicial inquiries on the coup attempt, and then the delegation headed to Ankara courthouse for hearing of the key suspect.
Kemal Batmaz, who is accused of being the "second-in-command" of the coup attempt, was brought to the hearing room for questioning, but he reportedly refused to provide any information.
Former colonel Hakan Biyik and the former rear admiral Halil Ibrahim Yildiz, who were secret witnesses, were also heard through video conference system.
A copy of the cellphone images belonging to Batmaz and another suspect Hakan Cicek are dispatched to the U.S. delegation, the agency reported.
The questions were asked by Turkish officials and additional supplementary questions by U.S. officials were also posed to the suspects.
The questions were about the U.S. inquiry and Turkey's investigation into Gulen movement, along with the extradition of Fethullah Gulen, according to the agency.
The U.S. prosecutors launched a preliminary inquiry into allegations of organized crimes, such as visa irregularities and money laundering by Gulen-linked foundations and individuals in the country.
In June, Turkish Foreign Minister Mevlut Cavusoglu said that the FBI began to investigate the group's breaches of U.S. laws. Gulen movement is operating several charter schools in the U.S.
Gulen is accused by Ankara of orchestrating a failed coup attempt on July 15, 2016. The Turkish government declared a state of emergency and launched a massive crackdown on Gulen's supporters in the aftermath of the coup attempt.
Turkish Justice Ministry has sent several files to Washington to beef up its evidences in demanding the extradition of the Islamic cleric.
Gulen has lived in self-imposed exile in the U.S. state of Pennsylvania since 1999.
In December last year, Cavusoglu said that there is a serious investigation into the group launched by the FBI in 15 states and the U.S. probe "seemed to have started bearing fruit."
"Moreover, arrests started in some states, including New Jersey," he added.
Washington has been reluctant on extradition of Gulen on the argument that the evidences were not sufficient, causing strain in bilateral ties of the two NATO allies.
"Our demand (for Gulen's extradition) is not officially rejected. As we find new evidence, we send it to the U.S. Administrative and criminal investigations are ongoing," Turkish Justice Minister Abdulhamit Gul said last week.
During the recent G20 summit in Argentina, U.S. President Donald Trump told Turkish President Recep Tayyip Erdogan that they are "working on extraditing Gulen and other people."
However, the White House clarified the U.S. position.
"The only thing he (Trump) said is that we would take a look at it," Sarah Sanders, the White House spokesperson, told reporters in December last year.
The visit of U.S. delegation came amid thawing in tensions between Ankara and Washington after U.S. pastor Andrew Brunson, who was on trial over terrorism-related charges in Turkey, was released in October 2018.