King Charles III was said to be unhappy by his siblings' show of support for the embattled Prince Andrew.
Pictures of Andrew at a shooting party on the Windsor estate alongside Prince Edward and Prince Andrew were met with a frosty response from the palace, according to The Mail on Sunday.
The gathering, which took place two days before His Majesty's 74th birthday, had intended to be a show of support for Andrew, who continues to fall foul of the monarch amid accusations surrounding his former involvement with convicted sex offender Jeffrey Epstein.
Prince Andrew stepped down from royal duties and the Queen stripped him of his military affiliations and patronages in the wake of a sex scandal earlier this year.
He denied the allegations against him and later came to an out of court settlement, reportedly worth £12 million with his accuser Virginia Giuffre. The settlement is not an admission of guilt.
A source told the Mail on Sunday that the King had decided not to attend the shoot and was unhappy about Andrew being there.
"King Charles was said to be displeased that Edward and Anne had been publicly meeting up with Andrew and wanted it made clear that he had not been part of the shoot," the source said.
The source added that Anne and Edward had been "privately concerned" about Andrew and "wanted to check on him", but that Charles is of the view that Andrew "should not be in the public eye" and that His Majesty was "not thrilled at all".
While Andrew is expected to be among the royals at Christmas, he will not be included in the family's annual walk to St Mary Magdalene Church on Christmas Day.
Last week, it emerged that Andrew was plotting a "fightback" into public life and believes this may still be possible, after his accuser, Virginia Giuffre, dropped a case she had brought against American lawyer Alan Dershowitz.
