The Duke of York can request the unsealing of a 2009 settlement agreement that his lawyer claims protects him from a lawsuit alleging he sexually assaulted a girl two decades ago, a US judge has said.

Manhattan Judge Loretta Preska said in a written order that Andrew can seek the information to support arguments that the agreement between Virginia Giuffre and the late financier Jeffrey Epstein disallow her lawsuit against the prince.

Epstein, 66, was found dead in his cell at a Manhattan federal jail in August 2019 while he awaited a sex trafficking trial. The death was ruled to be a suicide.

On Monday, attorney Andrew Brettler, representing the prince, told a Manhattan federal judge that he believes the settlement agreement “absolves our client from any and all liability”.

Mr Brettler spoke at the first court hearing to result from the August lawsuit, in which Ms Giuffre alleged that Andrew abused her on multiple occasions in 2001 when she was under 18. Andrew has said the abuse never happened.

Mr Brettler’s comment on Monday was referenced in court papers submitted by lawyers for Ms Giuffre as they asked a judge to rule that the prince was properly notified of Ms Giuffre’s lawsuit. They said the prince was “actively evading” formal efforts to serve him with Ms Giuffre’s lawsuit.

The lawyers noted that Mr Brettler planned to raise a defence based on the 2009 settlement between Ms Giuffre and Epstein of a Florida state case to which Andrew was not a party.

Judge Preska has presided over requests to unseal large portions of court filings related to a lawsuit Ms Giuffre brought against Epstein associate Ghislaine Maxwell in 2015.

The defamation lawsuit, which alleged Maxwell subjected Ms Giuffre to “public ridicule, contempt and disgrace” by calling her a liar, was settled and the case dismissed in May 2017.

The judge referenced the prince in an order rejecting attorney Alan Dershowitz’s attempt to unseal “a settlement agreement” that was designated confidential and sealed as part of records in the lawsuit Ms Giuffre brought against Maxwell.

The judge said Mr Dershowitz, who claimed he was seeking the unsealing “as a matter of professional ethnics” because he believes Ms Giuffre’s claims in the lawsuit against the prince are barred by the settlement, cannot seek the records because he is not a party to the lawsuit against Andrew.

“To the court’s knowledge, Mr Dershowitz has not been commissioned as a roving ethics monitor,” Judge Preska wrote.

“The court notes, however, that parties who have standing … and perhaps Prince Andrew, who has not been heard from … may seek to lift the protective order for valid reasons,” she added.

Ms Giuffre’s lawyers said the prince was “working with” Dershowitz to get a copy of the settlement papers unsealed “so he can share it with Prince Andrew”.

Maxwell, 59, is awaiting a November trial on sex trafficking charges that allege she procured girls for Epstein to sexually abuse for at least a decade beginning in 1994. She has pleaded not guilty.