BBC TV reported on Thursday that police had arrested King Charles' younger brother, Andrew Mountbatten-Windsor, on suspicion of misconduct in public office over his links to Jeffrey Epstein.
Earlier, newspapers reported that six unmarked police cars and around eight plain-clothed officers had arrived at Wood Farm on the Sandringham estate in eastern England earlier on Thursday.
Thames Valley Police said earlier this month officers were considering allegations that Mountbatten-Windsor had passed confidential government documents to the late sex offender, according to files recently released by the US government.
Mountbatten-Windsor, the second son of the late Queen Elizabeth, has always denied any wrongdoing in relation to Epstein, and said he regrets their friendship but has not responded to requests for comment since the latest release of documents.
Thames Valley Police did not have an immediate comment.
