Britain’s Prince Andrew is refusing to cooperate with U.S. investigators overseeing deceased Jeffrey Epstein’s sex trafficking investigation, according to Manhattan’s top prosecutor.

“Contrary to Prince Andrew’s very public offer to cooperate with our investigation into Epstein’s co-conspirators, an offer that was conveyed via press release, Prince Andrew has now completely shut the door on voluntary cooperation and our office is considering its options,” U.S. Attorney for the Southern District of New York Geoffrey Berman said at a press conference on Monday.

Neither Berman, nor his spokesman, James Margolin, would elaborate on what options are under consideration to impel Prince Andrew’s cooperation. The top Manhattan prosecutor previously noted the Duke of York’s non-involvement in the matter, saying in January that FBI had contacted the royal’s lawyers and requested to interview him. “To date, Prince Andrew has provided zero cooperation,” he said.

Andrew announced last year that he was withdrawing from his royal duties amid renewed attention of his friendship with Epstein and a woman’s claim that she had several sexual encounters with the prince, starting when she was 17.

Virginia Roberts Giuffre says that after meeting her in Florida in 2000, Epstein flew her around the world and pressured her into having sex with numerous older men, including Andrew, two senior U.S. politicians, a noted academic, wealthy financiers, and the attorney Alan Dershowitz, who is now part of President Donald Trump’s impeachment defense team.

All of those men have denied the allegations.

Giuffre has said she had sex with Andrew three times at Epstein’s request, including once in London in 2001 at the home of Epstein’s girlfriend, Ghislaine Maxwell.

Andrew and Maxwell have both denied any knowledge that Epstein was sexually abusing teenage girls.

The Associated Press contributed to this report.