Despite a pledge to comply, Prince Andrew has provided "zero" cooperation with the Jeffrey Epstein inquiry, New York prosecutors said.
"The Southern District of New York and the FBI have contacted Prince Andrew's attorneys and requested to interview Prince Andrew and to date Prince Andrew has provided zero cooperation," US Attorney for the Southern District of New York Geoffrey Berman told media on Monday.
"He publicly offered, indeed in a press release, to cooperate with law enforcement investigating the crimes committed by Jeffrey Epstein and his co-conspirators."
Buckingham Palace declined to comment when reached by BuzzFeed News.
In November, Prince Andrew stepped back from public duties "for the foreseeable future" over the "disruption" of his association with the late Epstein.
"I continue to unequivocally regret my ill-judged association with Jeffrey Epstein," Prince Andrew said in a statement.
"Of course, I am willing to help any appropriate law enforcement agency with their investigations, if required."
But Berman, speaking outside Epstein's former Manhattan mansion, said the Duke of York has not followed through.
Epstein was found dead in his New York jail cell last summer and his death was ruled a suicide. He was arrested in July and accused of running a sex trafficking operation in which he allegedly sexually abused dozens of underage girls, some as young as 14, in his New York and Florida homes between 2002 and 2005.
In August, Prince Andrew released a statement defending his relationship with Epstein, saying he had never participated in the alleged sexual abuse and at no point did he "see, witness or suspect any behaviour of the sort that subsequently led to his arrest and conviction."
The prince also said he saw Epstein "infrequently and probably no more than only once or twice per year."
One of the alleged victims, Virginia Giuffre, has said she was forced to have sex with the prince when she was 17 and under Epstein's control.
In a November interview with the BBC, Prince Andrew claimed Giuffre's account was false because she described him as sweating on a dance floor. He said he was unable to sweat at the time.
"There's a slight problem with the sweating because I have a peculiar medical condition which is that I didn't sweat at the time," Andrew told the BBC. "I didn't sweat at the time because I had suffered what I would describe as an overdose of adrenaline in the Falklands War when I was shot at."
Andrew was roundly mocked for the defense.