Prince Andrew's accuser Virginia Giuffre has agreed to hand over a secret document which could defeat her lawsuit.
Ms Giuffre's lawyers will hand the duke a copy of a 'release' signed in 2009 after her settlement with sex trafficker Jeffrey Epstein.
The Prince is being sued in New York by Ms Giuffre, now 38, who alleges he sexually abused her on three separate occasions when she was 17 – in London, New York and on serial US paedophile Jeffrey Epstein's island in the Caribbean. Andrew, 61, has consistently and fiercely denied the claims.
The Duke of York's attorney's will try to use the clause to exempt him from any fault in her claims against him, the Sun on Sunday reported.
Ms Giuffre's lawyers said the agreement was 'irrelevant' because it only offers protection to lawyers, employees, agents and heirs.
Her lead lawyer, David Boies, said he was happy to hand the document over to Andrew's team in a legal document filed in New York this week.
Virginia Giuffre's lawyers will hand the Duke of York a copy of a 'release' signed in 2009 after her settlement with sex trafficker Jeffrey Epstein. Pictured, Ms Giuffre and the Prince in 2001
The Prince (pictured in Windsor in April) is being sued in New York by Ms Giuffre, now 38, who alleges he sexually abused her on three separate occasions when she was 17
Mr Boies said: 'Although we believe that the release is irrelevant to the case against Prince Andrew, now that service has been accepted and the case is proceeding to a determination on the merits, we believe that counsel for Prince Andrew have a right to review the release and to make whatever arguments they believe appropriate based on it.'
It comes as Prince Andrew has dramatically changed his legal strategy to fight sex abuse claims, with an ally last night saying: 'Now it's time to turn and fight back to clear his name.'
US lawyers tried to serve legal documents on Andrew at his home at Royal Lodge in Windsor, through the British courts and by sending them through the post
After a surreal legal 'cat and mouse' game, Andrew's lawyers finally acknowledged on Friday that the Prince had been served with legal papers. He now has until October 29 to respond.
A source with knowledge of the proceedings told The Mail on Sunday: 'The decision to bring in high-profile [US lawyer] Andrew Brettler to fight the civil case marks a significant turning point in approach, and the US team will be looking to robustly engage and challenge the claims from Mrs Giuffre in a bid to provide the Duke with a platform to finally clear his name.
'They will be looking to examine and dismantle the claims one by one.'
The news came as respected biographer Nigel Cawthorne, author of Prince Andrew: Epstein, Maxwell And The Palace, called on Andrew to relinquish his HRH title while the case continues.
The Prince is being sued in New York by Virginia Giuffre, now 38
'Andrew is supposed to be an officer and a gentleman, so he should do the decent thing and give up his HRH title,' said Mr Cawthorne. 'Harry and Meghan had to stop using their HRH status and they haven't been accused of anything. But in keeping his titles and his military roles, the Queen has been tainted by the accusations.'
US lawyers tried to serve legal documents on Andrew at his home at Royal Lodge in Windsor, through the British courts and by sending them through the post.
A corporate investigator sent to the gates of Royal Lodge said that security staff there had been 'primed' not to accept the court papers. Ms Giuffre is seeking unspecified damages.