It's been called "grotesque" and "unjustifiable".

French magazine Closer have published photographs of the Duchess of Cambridge topless.

Catherine, also known as Kate, was sunbathing with her husband Prince William at a private estate in France when they were taken.

The royal couple are currently on a tour of Asia to celebrate the Queen's Diamond Jubilee.

In a statement issued by the couple's press office St James's Palace, the publication of the photos was compared to "the worst excessess of press and paparazzi during the life of Diana, Princess of Wales."

Diana, William and Harry's mother, died in a car crash in 1997.

Her brother blamed the media for having a hand in her death.

The statement said the couple had "every expectation of privacy in the remote house," adding that officials acting on their behalf are consulting with lawyers to consider what options may be available to them.

Legal commentator Christopher Mesnooh says the magazine could have a case to answer.

(SOUNDBITE) Lawyer, Christopher Mesnooh, saying (English):

"Under French law this would probably be qualified as an invasion of privacy."

However the French magazine may already have taken any fines into account.

(SOUNDBITE) Lawyer, Christopher Mesnooh, saying (English):

"In these situations the damages are low: several thousand euros, perhaps 10 to 15,000 euros in extraordinary cases. So when you do an economic analysis of the number of issues that it's going to sell compared to the potential legal liability, it's certainly from a financial standpoint very interesting for the magazine to have published these photos.

This is the second time in a month the British royal family has been rocked with exposés in the media.

Prince Harry was photographed in August naked in a Las Vegas hotel.