The pictures of William and Kate frolicking on the beach in Mustique are set to go global, with reports suggesting they have already been sold in at least four countries around the world, including the USA. William has not launched legal action and appears to accept he is powerless to prevent their global publication.

The pictures are now widely available on the internet after users scanned them into sites like tumblr last night, hours after their first publication in the Italian magazine Chi.

The notable exception to the global publication binge is the British media, who are unlikely to publish the pictures following the recent furore over press intrusion in the UK.

The Australian magazine Woman's Day has now confirmed it is printing the pictures, as well as photographs of Kate's sister Pippa in a bikini.

Intriguingly, the magazine's editor has claimed they were taken by a member of the public on a public beach.

Editor Fiona Connelly told an Australia's News Ltd that the images had been taken by a fellow tourist and not by a paparazzi photographer.

It is reported the magazine paid nearly £100,000 for the 39 images of the royal couple.

"She is on a public beach and she was mingling with holidaymakers. These photos have not been taken by a professional photographer hiding in the bushes. They are not nude photos taken with a telescopic lens from inside a private villa. These are images showing her on a happy holiday ... and she looks amazing.

"The last time we saw Kate in public she was very ill. She was coming out of hospital, which means there is even more reason to celebrate her looking so healthy and glowing."

The set of photos is also said to include images of Kate's sister Pippa Middleton.

Connelly added it was a "very different situation to the nude photos", which were published by Italian magazine Chi and the UK's Daily Star last year.

The long-lens pictures showed Kate Middleton sunbathing topless on the roof of a private chateau in France with her husband Prince William.

A St James's Palace spokesperson told the Royalist that the decision was "a clear breach of the couple's right to privacy".

"We are disappointed that photographs of the Duke and Duchess on a private holiday look likely to be published overseas," he said.