They were seen wearing masks resembling King Charles and Queen Camilla during their demonstration.

A heavy police presence has been seen near the Sandringham estate as police continue their investigation into Andrew Mountbatten-Windsor.

The Spectator‘s Tim Shipman reported: “‘The Palace is terrified’ about what could potentially happen, my man with his snout in the royal rosebushes informs me.”

The writer added: “They would like to see him tried and convicted and sent to prison, or tried and cleared, because that would at least draw a line under things.’ This is fairly extraordinary.”

Speaking of the sisters, a source revealed that Beatrice, 37, and Eugenie, 35, are “utterly horrified” and “very distressed”.