French prosecutors have been tipped off with the name of the paparazzi photographer who took the topless pictures of Kate Middleton.
The authorities had been seeking the identity of the snapper understood to be a man since Prince William launched a criminal complaint in Paris. It is believed up to 200 intimate shots were taken of the Duchess of Cambridge.
The paparazzo is now likely to face a police grilling. If found guilty of taking the pictures of Kate on the balcony of a holiday chateau in Provence, he could be jailed for up to one year and fined £36,000 for breach of privacy.
A royal source said: "William and Kate are determined to bring the person who took those photos to justice and they're pushing hard for a custodial sentence. They want to make an example of this person."
In September, Kate, 30, was devastated when pictures of her wearing nothing but a pair of bikini bottoms were published in the French gossip magazine, Closer.
She and husband William, 30, had been staying a week earlier at the Chateau d'Autet owned by the Queen's nephew, Lord Linley when the long lens photos were taken.
Closer editor Laurence Pieau has confirmed the magazine hired a freelance photographer to watch the Duke and Duchess of Cambridge during their holiday but the publication is still refusing to reveal his name. Under French law, Closer magazine has the right to protect the identity of the snapper because of the country's protection of journalistic sources regulations.
Pieau came under worldwide criticism for her decision to publish the snaps as Kate and Wills were on a royal tour of the Far East for the Queen's Diamond Jubilee celebrations.
At the time, she said: "What we saw in the pictures was a young couple who are just married, who are in love, who are beautiful, she is the princess of the 21st century. She's a young woman who's topless, just like the ones who can be seen on all of the beaches of France and the world. These pictures are full of joy, not degrading."
Closer, owned by ex-Italian PM Silvio Berlusconi's daughter Marina, has been prevented from distributing the pics by an injunction but they have been touted across Europe. Italian magazine Chi has printed 18 of the photos, the Irish Daily Star editor was suspended after publishing them and a gossip magazine in Denmark printed five pages of the snaps.
The probe into the identity of the photographer is being led by officials in the Paris suburb of Nanterre. Confirming police are now aware of his name, public prosecutor Marie-Christine Daubigney said yesterday: "This new information regarding the photographer will be passed on to investigating magistrates."
One French photographer who stalked Princess Diana in the weeks leading up to her death in the Paris car crash in August 1997, emphatically denied that he was responsible for taking the Kate pictures.