image source, Virginia Robertsimage captionVirginia Giuffre, then Roberts, was pictured with Prince Andrew in London in 2001
The Duke of York's lawyers may legally challenge the High Court's decision to notify the prince about allegations of sexual assault filed in a US court.
Using the Hague Service Convention, lawyers for Virginia Giuffre, Prince Andrew's accuser, asked the court to serve the duke with papers informing him of the civil case in New York.
The High Court initially rejected the request but then reversed its decision.
The Judicial Office said any challenge must be made by the end of next Friday.
In a statement, it said: "Lawyers for Prince Andrew have indicated that they may seek to challenge the decision of the High Court to recognise the validity of the Hague Convention request for service made by Ms Giuffre's lawyers.
"The High Court has directed that any challenge must be made by close of business on 24 September."
A spokesman for Prince Andrew declined to comment.
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The Hague Service Convention is a treaty that governs requests between countries for evidence in civil or commercial matters.
It allows Ms Giuffre's legal team to ask the High Court in London to formally notify Prince Andrew about her civil action.
The High Court initially rejected the request by Ms Giuffre's lawyers, citing an issue with the application, but later accepted it after they provided further information, which clarified that they were legally permitted under US law to make the Hague Convention submission for assistance.
The prince does not face the prospect of an extradition hearing, as this applies only to criminal charges, not civil cases.
Ms Giuffre, now 38, was an accuser of the billionaire sex offender Jeffrey Epstein who died in prison in 2019.
She claims she was sexually assaulted by the prince at three locations, including New York City.
Ms Giuffre – then known as Virginia Roberts – says she was assaulted at the London home of Epstein associate Ghislaine Maxwell, and at Epstein's homes in Manhattan and Little Saint James, in the US Virgin Islands.
Her case claims Prince Andrew, 61, engaged in sexual acts without Ms Giuffre's consent, including when she was 17, knowing how old she was, and "that she was a sex-trafficking victim".
The Queen's second son has consistently denied the claims and, in 2019, told BBC Two's Newsnight programme: "It didn't happen.
"I can absolutely categorically tell you it never happened.
"I have no recollection of ever meeting this lady, none whatsoever."
At the first pre-trial hearing in New York, on Monday, the prince's lawyer, Andrew Brettler, argued he had not been properly served notice of the case under either UK or international law.
Ms Giuffre's lawyers said that papers had been left with a police officer at the gates of Prince Andrew's Windsor home last month – and so was successfully "served".
During the hearing, held via telephone conference, Mr Brettler also described the civil case against the prince as "baseless, non-viable [and] potentially unlawful".