Lieutenant Colonel Levent Turkkan, the aide of Chief of Turkey's General Staff Hulusi Akar, admitted having links to the Fetullah Terrorist Organization (FETO), which he said was the main perpetrator of Friday's failed coup attempt.
In his testimony released early Wednesday, Turkkan said he was a loyal member of the FETO group since his youth.
"I am a member of the parallel state, or FETO. I have served this community for years voluntarily. I have obeyed the orders and instructions of the big brothers exactly," he confessed.
Turkkan was detained earlier for his alleged link to the deadly coup attempt, which occurred on late Friday when rogue elements of the Turkish military tried to overthrow the country's democratically elected government.
At least 240 people, including members of the security forces and civilians, were martyred in Istanbul and Ankara and nearly 1,500 others wounded as they protested against the coup.
Turkkan said he comes from a poor family in the northwestern district of Bursa and met the group during his secondary school years while he was staying at a dorm.
"Since I was five, my biggest wish was to become a military officer. [...] And my dream of becoming a military officer pleased them," he said, adding that he entered the military school entrance exam in 1989.
Turkkan said he was a bright student and that he was sure he would pass the exams with his own efforts.
"But the night before the exam, big brothers gave me the [answered] questions of the exam in a house belonging to them in Bursa," he said.
Continuing to see his "big brothers" during and after his military school years, Turkkan said he "served them during missions in Istanbul, Trabzon, Diyarbakir, Lefkosa, Kiziltepe and lastly in Ankara."
Former top general eavesdropped
Turkkan also confessed he spied on Former Chief of Staff Necdet Ozel during his post between 2011- 2015. Turkkan said he initially served as deputy aide and later became an aide after his chief retired.
Turkkan said he fulfilled the Gulen movement’s orders after becoming a close aide in the General Staff.
"I was spying on [former] Chief of Staff Necdet Ozel all the time. I put a recording device in the room in the morning and took it back in the evening hours," Turkkan said. "The device has its own capacity and could wiretap for 10-15 hours."
During the questioning by the prosecutors, Turkkan admitted he received the device by a person who claimed to be working at the Turk Telecom, Turkey's telecommunications center.
“[He] ordered me to eavesdrop on the general [Necdet Ozel]. He told me ‘We will tap him for information purposes; nothing is going to happen.’ I did not question and took the device,” he said.
Turkkan said he had at least two recording devices and returned the device once its capacity was full.
Lt. Col. Turkkan also admitted that Major Mehmet Akkurt – whom Turkkan claimed to be a member of Gulen movement and worked closely with -- spied on high-ranking generals, including the Chief of Staff Hulusi Akar.
He did not specify the exact time of when they tapped Akar.
“I think the movement has been spying on those generals to know what is going on inside the armed forces,” Turkkan confessed.
Once General Hulusi Akar was promoted as the Chief of Staff, Turkkan said he stopped wire-tapping.
During the interrogation, Turkkan also provided information on how the Gulen movement was organized inside the Turkish military.
“I believe 60-70 percent of those people who have been accepted inside the armed forces since 1990s are Gulen-linked people,” he said.
Turkkan said he received information about the military coup on July 14 at around 10.00 am local time (1900GMT) from Staff Colonel Orhan Yikilkan, who served as an adviser to the Chief of Staff.
"Yikilkan told me the President, the Prime Minister, the Chief of Staff and commander-in-chiefs will be arrested; that will be done [with] quietly; [the military coup] will be staged at 03.00 AM on early Saturday [July 16],” Turkkan said.
Turkkan said he visited his brother to check whether he was aware of military take-over, but failed to see him.
He told the prosecution that he met with other members of the movement in his brother’s home.
“When I asked them, they angrily told me ‘How do you know? Who told you these? Did you tell anyone?’… They told me to keep quiet,” Turkkan said.
After the thwarted attempt, Turkkan said he surrendered to the military officials who turned him in to the police.
Turkkan said he felt regret for taking part in the violent coup.
"Until the coup, I thought Gulen movement was acting for only God's sake and Gulen himself had a spiritual identity," Turkkan said.
"Until today, I never thought Gulen movement was a traitor. But now, I [have] realized what they really are. They [the members of FETO] are bloodthirsty. I have never seen Fetullah Gulen, but he is the same," he said.
“I feel regret not only for taking a part in this but also becoming a member of the Fetullah Gulen movement,” he added.
The government has repeatedly said the attempted coup was organized by followers of U.S.-based preacher Fetullah Gulen, who is accused of a long-running campaign to overthrow the state through supporters within the Turkish state, particularly the military, police, and judiciary, forming the so-called parallel state.