Prince Andrew's accuser Virginia Giuffre and sex offender Jeffrey Epstein's 2009 settlement, which could be key to a civil case involving the Duke of York, was made public on Monday.
The settlement was reportedly reached between Giuffre (formerly known as Virginia Roberts) and convicted sex offender Jeffrey Epstein, who died in prison in 2019.
The document, disclosed by a New York court, reveals the financier paid her $500,000 (£371,000) to end her claim.
Ms Giuffre is suing the Duke of York in a civil case for allegedly sexually assaulting her when she was a teenager. He has consistently denied the claims.
The document was released ahead of a critical hearing on Tuesday in the civil case involving Prince Andrew.
The prince's lawyers say this previously-secret 2009 deal means she cannot sue him - because she agreed to end all legal action against anyone connected to the offender who could be described as a "potential defendant".
Some critics believe that Prince Andrew’s assault case could damage the monarchy on a much wider scale. Last week, Andrew's friend Ghislaine Maxwell was found guilty of recruiting underage girls to be sexually abused by her ex-boyfriend Epstein.
However, Prince Andrew's lawyers think differently and claim the 2009 settlement- made public for the first time - could release him from liability in the case brought by Giuffre, who accused the royal of sexual assault.
Brettler, who represents the duke, previously told at New York hearing the agreement "releases Prince Andrew and others from any purported liability arising from the claims Giuffre asserted against the second son of the Queen."
US District Judge Lewis A Kaplan, who is presiding over the civil case, is due to hold a video teleconference on Tuesday when a request by Prince Andrew's legal team to dismiss the case will be heard.