A French court opened a criminal investigation on Tuesday into charges that photographers and France's Closer magazine breached the privacy of Britain's Prince William and his wife, the Duchess of Cambridge, by publishing topless photos of her.
In a scandal that has incensed much of the British public and rekindled a debate on privacy laws, lawyers for the royal couple are seeking damages from the weekly gossip magazine over its publication of the photos in a five-page spread on Friday.
The court in Nanterre, near Paris, said it would investigate whether there are grounds for criminal charges against Closer, published by Italy's Mondadori, and the paparazzi who snapped pictures of the Duchess from a distance while she sunbathed topless with William at a villa in southern France.
The couple have also launched a civil suit against Closer over the photos, which show the former Kate Middleton slipping off her bikini top, relaxing on a sun lounger and at one point pulling down the back of her bikini bottoms.
Buckingham Palace has called the photo spread a "grotesque" invasion of the royal couple's privacy.
British newspapers, fighting for their reputation after a string of scandals, have agreed not to publish the images, as has the British edition of Closer which is managed separately, and instead are condemning the photographer.
The Sun tabloid screamed: "Find Le Rat" on its front page on Tuesday and said the photographer would be hunted down and faced jail.
On Monday, the publisher of tabloid The Irish Daily Star suspended its editor after the newspaper broke ranks with Irish and British peers, publishing pages from Closer with the photographs in its Saturday edition.