A French magazine has published topless pictures of the Duchess of Cambridge.
The royal couple are said to be furious, and consulting with French and British lawyers.
In a statement from St James's Palace the couple were said to be appalled by their privacy being invaded in such a "grotesque and unjustifiable manner".
But what can the couple do?
We look at what the law says, and what restrictions are on the press both here and in France.
French Privacy Law
France has some of the strictest privacy laws in the world, but in recent years fines imposed on the press have gradually reduced and many magazines are now willing to accept this small cost in order to win readers.
The country's laws on the issue come from a single, broad-reaching sentence in Article 9 of the Civil Code which simply states "Everyone has the right to privacy".
The right to privacy is also written into the country's constitution which protects a person's private life and also prohibits the unauthorised taking of photographs and their publication.
According to privacy lawyer Charlotte Harris these laws mean the publication of the photos of the Duchess could be fought with civil and criminal action against both the photographer and the magazine.
Talking on BBC News Ms Harris said she was dismayed by the photographs being published, but was totally shocked to hear they had been published in France.
In the past, many private stories including that of former President Mitterrand's illegitimate daughter have been hidden by the press, but since public figures such as Sarkozy began flaunting their private lives French judges have been reluctant to impose heavy penalties on the press.
While the royal couple have missed the opportunity to stop publication of the photographs, their lawyers are reportedly now looking at their legal options.
UK Privacy Law
In the UK, privacy law has not advanced as quickly as in France and there is still no freestanding right to privacy in common law.
Instead cases are often based upon laws concerning breach of confidence, as well as relying heavily on case law which looks at significant previous cases.
One such case was that of formula 1 boss Max Mosley who won £60'000 in damages in a landmark case against the News of the World after they published pictures of him with several prostitutes.
Another key set of guidelines is found in the European Convention on Human Rights.
In Article 8 of the convention, which applies in both the UK and France, it says all have a right to respect for one's "private and family life, his home and his correspondence".
It is here that the recently published pictures of Prince Harry naked in Las Vegas differ to these of Kate.
Whereas Harry was photographed during a party with members of the public, the Duchess of Cambridge was in a private property on a private holiday with her husband, Prince William.
All British newspapers have resultantly rejected offers to buy the photos, but they have been published today by 'Closer' magazine in France.
Press Complaints Commission
In the UK there is also an independent press complaints commission which monitors press standards.
While it doesn't have legal powers, the PCC does lay out a clear code of practice by which UK magazines and newspapers are expected to abide.
On privacy, article 3 of the Editors' code of practice says: "It is unacceptable to photograph individuals in private places without their consent".
It describes a private place as anywhere an individual could have a reasonable expectation of privacy.
The photos of the Duchess were taken during a short break last week in France when the couple stayed in a remote chateau belonging to the Queen's nephew, Lord Linley.
Appearing on BBC Breakfast, Paul Horrocks, former chairman of the PCC said "this would have been different if the photos were taken on a beach or in park," these photos were taken on a private property with a long distance lens.
While a royal spokesperson said this morning that this publication has set back progress made in royal privacy by 15 years, it is however significant that UK newspapers have not shown the photographs.
Mr Horrocks emphasised this saying significant progress has been made.
"The paparazzi photos are still around, but they're not used to the same extent. The British media have not used them."
The Duchess of Cambridge previously took action against paparazzi in 2010 who took pictures of her playing tennis were published in Germany.