Prince Andrew is ready to launch a $100 million lawsuit against his accuser Virginia Roberts if she repeats sex claims against him in her upcoming memoir.

Legal sources close to the Prince - who has consulted US lawyers in a bid to overturn a settlement he reached with Ms Roberts last year - say he will ‘go on the attack' should she repeat the allegations.

The Duke of York has hired high-powered LA lawyers Andrew Brettler and Blair Berk for an attempt to get Ms Roberts to retract any claims and possibly secure an apology.

Last night, a source familiar with the case told this newspaper: ‘The minute she writes anything that repeats the original claims against him she will be hit with a $100 million (£81 million) defamation lawsuit. Andrew and his lawyers are ready to go on the attack.

Then her claims will be put under scrutiny for the first time in a court of law.'

Lawyers for Ms Roberts declined to comment last night, but a source close to her insist her settlement with the Duke does not preclude her from writing about him, saying: ‘She will be able to discuss Prince Andrew.'

Ms Roberts, now 39 and going by her married name of Giuffre, claimed she was forced to have video sex with the Prince when she was 17, having been trafficked by convicted paedophile Jeffrey Epstein.

In the out-of-court settlement reached last February, Andrew accepted no blame and continues to strenuously deny any wrongdoing.

He reportedly paid her £12 million but insiders say the figure was closer to £3 million.

His mood is said to have been ‘buoyed' by a settlement reached between Ms Roberts and US lawyer Alan Dershowitz in November in which she admitted she ‘may have made a mistake' in accusing Mr Dershowitz of abusing her.

Mr Dershowitz said last night: ‘Virginia Giuffre has now finally recognised that she may have made a mistake and I hope that this can help bring out the truth about other accusations, including the Prince.'