Princess Anne left hurt by Sarah Ferguson's viral photos: 'Unbelievable'

King Charles' only sister Princess Anne allegedly lost her cool over her former sister-in-law Sarah Ferguson's upsetting viral photos.

The Princess Royal, 75, could hardly hold back her emotions and flew into a rage to teach Fergie a lesson after seeing her 'unbelievable' pictures, according to a new bombshell claim.

Ferguson made headlines in the early 1990s over her alleged affair with American "financial advisor" John Bryan. The two were photographed enjoying the sun in the south of France.

Royal author Andrew Lownie penned in his book "Entitled: The Rise and Fall of the House of York" that the Princess was left so frustrated by the photos appearing in the media.

The pictures and Sarah's reaction to them invited wrath from the late Queen Elizabeth II's eldest daughter.

Fergie purportedly travelled to Balmoral to be with Andrew and the other royals after holidaying with Bryan. It is claimed that she then came down for breakfast to find her in-laws reading the newspapers and looking at the photos.

'She entered the breakfast room to find everyone reading the story and fled,' Lownie wrote, according to The Mirror.

One person, who was present, told the duchess's biographer Chris Hutchins that the Princess Royal 'came close to throttling' Sarah, and at dinner told her what she thought of her: 'There was not one voice raised against Anne.'

A servant who was at Balmoral during the incident claimed that Sarah 'acted in the strangest way,' adding: 'You would have thought she was the person wronged, as if she had every right to go on holiday with another man.'