Police are investigating an allegation that Andrew Mountbatten-Windsor behaved inappropriately towards a woman at Royal Ascot.
The incident is alleged to have taken place in 2002, when Andrew’s mother Queen Elizabeth II attended the Berkshire festival with other senior royals, according to The Times.
Andrew was photographed at the event alongside his daughter Princess Beatrice and the now King Charles.
It is unclear whether the claim about Andrew’s alleged behaviour was reported to police at the time or more recently.
It comes as Mountbatten-Windsor is currently under investigation by Thames Valley Police for misconduct in public office.
The police investigation was prompted by the release of the Jeffrey Epstein files by the US Department of Justice.
Mountbatten-Windsor has consistently and strenuously denied any wrongdoing.
The former Duke of York was arrested on his 66th birthday on February 19 and interviewed under caution before being released under investigation.
Searches were also carried out at his former homes in Windsor and Norfolk. Detectives are understood to be working through evidence recovered during the operation.
In an update this week, detectives announced that a misconduct in public office probe into the former prince has broadened to consider a wide range of possible crimes that fall under the broad banner of misconduct in public office.
The legal definition of the offence can include a wide range of conduct, including sharing confidential financial information, financial misconduct, wilful neglect of duty, and sexual misconduct.
It also covers corruption and improper interference, conflict of interest, perverting the course of justice, dishonesty or fraudulent conduct, misconduct leading to personal gain.
Thames Valley Police had made an appeal for potential ‘victim survivors’ to come forward.