Activists have hung a picture of former prince Andrew with notorious sex offender Jeffrey Epstein in the heart of Buckingham Palace.
It is understood protesters from the campaign group Republic made their way into the Palace as tourists after buying a ticket and made their own way to the Throne Room.
The banner was emblazoned with the words ‘what did you know?’, a slogan used by campaigners since Andrew was stripped of his titles last year.
Graham Smith, Republic’s chief executive, told security at the Royal Family’s most famous residence is ‘more relaxed than you might think’.
He added: ‘Wardens asked us to leave, but we were leaving already.’
Andrew’s relationship with Epstein led to him stepping down as a working royal in November 2019, and then being stripped of his titles by King Charles last year.
Epstein survivor Virginia Giuffre said she had been trafficked to the then-prince, and a civil lawsuit she filed against him was settled in February 2022.
Andrew denies any wrongdoing.
Since the former Duke of York was cut off by the Royal Family, activists have continued to ask questions about how much the King knew about the allegations against him.
Mr Smith said: ‘This question isn’t going away.
‘It is simply not believable to think that Charles and William weren’t briefed years ago about the numerous allegations against Andrew.’
The Royal Collection Trust, which organises the tours around the Palace, declined to comment on security matters.

World Affairs Correspondent