Kate Middleton and Prince William keep smiling on tour as they launch criminal complaint over topless pictures
France's criminal prosecutors will then decide whether the case is worth pursuing, but if proceedings go ahead, they could technically end in a 1-year prison sentence and a £36,000 fine
for the magazine's editor Laurence Pieau and the photographer.
Wills and Kate's lawyers are also going to the civil courts to seek damages and an injunction preventing further publication of the images.
Closer France published the long-lens pictures of Kate - which were taken as she sunbathed in Provence earlier this month - in a 5-page spread on Friday.
Italian magazine Chi are also set to print a 26-page special, while the Irish Daily Star included the pictures over the weekend.
Kate and William, both 30, will continue with their Diamond Jubilee tour of Asia and the South Pacific as the court case begins.
They remained upbeat as they visited the Solomon Islands yesterday.