Andrew Mountbatten-Windsor has been arrested on suspicion of misconduct in public office and is in police custody.
Thames Valley Police confirmed the arrest on Thursday following allegations made against the former prince after the release of millions of pages of files related to paedophile financier Jeffrey Epstein.
The arrest comes as pictures circulated online appearing to show unmarked police cars attending Wood Farm on the Sandringham Estate in Norfolk, with plain-clothed officers appearing to gather outside Andrew’s home.
Thames Valley Police previously said the force was reviewing allegations that a woman was trafficked to the UK by Jeffrey Epstein to have a sexual encounter with Andrew, and claims he shared sensitive information with the paedophile while serving as the UK’s trade envoy.
Searches are being carried out at addresses in Berkshire and Norfolk, the force said.
Assistant Chief Constable Oliver Wright said: “Following a thorough assessment, we have now opened an investigation into this allegation of misconduct in public office.
“It is important that we protect the integrity and objectivity of our investigation as we work with our partners to investigate this alleged offence.
“We understand the significant public interest in this case, and we will provide updates at the appropriate time.”