Former White House National Security Adviser Mike Flynn and his son were proposed $15 million to abduct Fethullah Gulen in Pennsylvania to illegally return him back to Turkey, according to Wall Street Journal’s (WSJ) sources on Friday.

Under the alleged proposal, Flynn and his son, Michael Flynn Jr., were to be paid as much as $15 million for delivering Fethullah Gulen to the Turkish government, people familiar with a private meeting between Flynn and Turkish government representatives told WSJ.

The discussions between Flynn and Turkish government reps “involved the possibility of transporting Mr. Gulen on a private jet to the Turkish prison island of Imrali.”

As part of a recent investigation launched by the Special counsel Robert Mueller, Federal Bureau of Investigation (FBI) agents have asked at least four individuals about a meeting in mid-December at the ’21’ Club in New York City, where Mr. Flynn and representatives of the Turkish government discussed removing Mr. Gulen, according to people with knowledge of the FBI’s inquiries, WSJ said.

Sources said the December meeting was a follow up to an earlier meeting on the same matter. Former CIA director James Woolsey earlier told media that Flynn met with Turkish government officials in September 2016 to forcedly send Gulen back to Turkey. “A covert step in the dead of night to whisk this guy away,” Woolsey described the plan underlining that he attended the meeting at the request of one of Mr. Flynn’s business associates. The September meeting was also attended by Turkish Energy Minister Berat Albayrak, also Erdogan’s son-in-law, and Turkish Foreign Minister Mevlut Cavusoglu.

“One person familiar with the alleged discussions about Mr. Gulen said Mr. Flynn also was prepared to use his influence in the White House to further the legal extradition of the cleric, who lives in Pennsylvania,” WSJ added.

Turkish government accuses Fethullah Gulen and his supporters of masterminding the July 15, 2016 coup attempt, a claim the Muslim cleric and his movement deny. President Recep Tayyip Erdogan and the government seeks Gulen’s extradition from the US however Washington has made clear so far that enough evidence backing up Gulen’s involvement in the failed takeover has yet to be delivered.