(CNN) Prince Andrew has "completely shut the door" on voluntarily cooperating with a US investigation into Jeffrey Epstein's co-conspirators, prosecutors in New York have said, despite the royal's public offers to help with any probe into the disgraced financier if required.
The US Attorney for the Southern District of New York, Geoffrey Berman, said his office was "considering its options" as it continues its investigation into the convicted pedophile's circle of associates.
The Duke has come under intense public pressure to explain his relationship with Epstein and allegations he had sexual encounters with an underaged girl, which he denies.
"Contrary to Prince Andrew's very public offer to cooperate with our investigation into Epstein's co-conspirators, an offer that was conveyed through press release, Prince Andrew has now completely shut the door on voluntary cooperation and our office is considering its options," Berman said at a press conference on Monday.
Buckingham Palace declined to comment when approached by CNN.
In November, Britain's Prince Andrew said in a statement he was "willing to help any appropriate law enforcement agency with their investigations, if required" after his widely-ridiculed appearance in a BBC interview, in which he was questioned about his relationship to Epstein.
Lawyers for Epstein's alleged victims have previously threatened to subpoena Andrew, though it is unclear whether he could be forced to speak to prosecutors.
One of Epstein's accusers, Virginia Roberts Giuffre, has alleged that she was forced into sexual encounters with the prince while she was underage. In a 2015 federal court filing, Giuffre alleged Epstein forced her to perform sex acts with several prominent men, including Prince Andrew in 2001.
All of those men have denied the allegations against them. In his November BBC interview, Andrew said he could not recall meeting Giuffre and suggested that a photo of the two of them may have been doctored.
Epstein, whose relationship with Andrew continued after the financier's conviction for sex offences, died by suicide in August while awaiting trial on federal charges that he sexually abused underage girls and ran a sex-trafficking ring.
The Duke of York said he trusted Epstein and conceded that he had stayed at Epstein's homes in Manhattan and Palm Beach, had been on Epstein's private plane and visited Epstein's private island. He also met with Epstein in 2010 in Central Park two years after the financier pleaded guilty to soliciting a minor for prostitution and was required to register as a sex offender.
His appearance on the BBC was widely criticized and the prince stepped back from his public duties in the aftermath of the interview.