A high-profile female journalist has been placed under formal criminal investigation in connection with topless pictures taken of the Duchess of Cambridge.
Laurence Pieau, the editor of French Closer magazine, was formally charged in connection with an alleged breach of France's strict privacy laws.
She now faces the prospect of a humiliating trial alongside at least two photographers and her publishing director, Ernesto Mauri.
Judicial sources in Paris arrested Ms Pieau earlier this month, but chose tonight to announce her new legal position
They also said that an unnamed 28-year-old Paris agency photographer had also been arrested and charged, while another was 'on the verge' of being charged.
Mr Mauri was charged in April alongside a photographer believed to be Valerie Suau, who admits taking images of Kate in the south of France during a holiday last September.
Ms Suau describes her own pictures, published in La Provence regional newspaper, as 'all decent'.
But she is suspected of having assisted at least one other photographer who took numerous snaps of the topless Duchess.
Kate and Prince William took legal action against Closer through their French lawyer, Aurelien Hamelle, who described the Duchess as a 'a young woman, not an object'.
He said the royal couple had suffered a 'grotesque breach of privacy' and felt 'violated' during a 'highly intimate moment during a scene of married life'.
Ms Suau, whose name is pronounced 'sewer', has kept a low profile ever since the case, but police arrested her in April.
Ms Pieau, meanwhile, has given numerous interviews in which she has justified the pictures, saying in December: 'I did my job as a journalist'.
The photographs of the Duchess sunbathing on the terrace of Viscount Linley's Chateau d'Autet, in Provence, on September 5th caused a public outcry in Britain.
Referring to Princess Diana's death in 1997, Mr Hamelle said it was 'just six days after the 15th anniversary of the cynical and morbid hunt which led to the death of William's mother'.
Mr Hamelle told a court in the Paris suburb of Nanterre that William and Kate could not have known they were being spied on and a photographer would have needed a long lens, even if he or she was on a public road.
The Duke and Duchess also launched criminal proceedings against the photographers under France's strict privacy laws.
The French media are protected from having to name their sources – including photographers – but the royal couple are said to have made it a personal crusade to discover who took the images.
Ms Suau has denied being responsible for taking any indecent images. She says she took pictures of Kate in her swimsuit but not topless.
Yet, despite her claims, no other photographer has been identified, nor even been placed in the area at the time.
Delphine Pando, representing the magazine, told the Nanterre court last year that topless photographs were no longer considered shocking.
She denied that the chateau was inaccessible to public view and claimed the magazine did not hold the rights to the pictures, so it could not be proved that it intended to republish them.
Ms Suau, who lives close to Chateau d'Autet, deep in the Provence countryside east of Avignon, told friends there was no sign of British or French police anywhere, so allowing 'any photographer who wanted' to take images.
Some were shot from a public road on a hill less than half-a-mile from the former hunting lodge, close to the medieval village of Viens, although it is possible to get closer on foot.
The road, and nearby path, offers clear views of the Chateau's raised swimming pool and its sun loungers, where Kate and William spent most of their four day break.
A Paris prosecutors source confirmed to AFP, France's national news agency, that Ms Pieau was charged earlier this month, along with the second photographer.