Kate Middleton Topless Pictures Anger Royals

The Duke and Duchess of Cambridge are considering legal options over the topless pictures French magazine Closer published on Thursday.

"We certainly feel a red line's been crossed," a palace source told PEOPLE.

VIEW KATE MIDDLETON TOPLESS PHOTOS HERE - NSFW

The topless pictures of Kate Middleton were taken during William and Kate's private holiday in France. The source also said that the mood at the palace back home is "one of anger and disbelief."

A statement from a St. James's Palace spokesman says, "Their Royal Highnesses have been hugely saddened to learn that a French publication and a photographer have invaded their privacy in such a grotesque and totally unjustifiable manner."

"The incident is reminiscent of the worst excesses of the press and paparazzi during the life of Diana, Princess of Wales, and all the more upsetting to The Duke and Duchess for being so," the statement continues. "Their Royal Highnesses had every expectation of privacy in the remote house. It is unthinkable that anyone should take such photographs, let alone publish them."

"The Duke and Duchess remain focused currently on their Tour of Singapore, Malaysia, Solomon Islands and Tuvalu on behalf of HM The Queen."

Meanwhile, A spokesman for the couple told Mail Online today: 'Their sadness has turned to anger and disbelief as we have learnt more about the photographs. We believe a red line has been crossed and we are consulting the French lawyers to see what, if any, action can be taken.

But in a show of unbelievable strength the Duchess of Cambridge managed to smile and laugh her way through a Diamond Jubilee tea party at the British High Commission.
Kate sipped tea and chatted to several guests including shoe designer Jimmy Choo.
She appeared determined not to let the strain of the morning's revelations show - laughing and chatting to the designer without an apparent care in the world - although William at times did appear to have the weight of the world on his shoulders.

Sources said the Duchess and her husband were 'hurt, shocked, furious and disgusted'.
The anger had not subsided for Prince William as they then left the capital of Malaysia for the next leg of their tour of south east Asia.