The Duke and Duchess of Cambridge faced fresh anguish and frustration yesterday after an Italian gossip magazine published photographs of Kate on a private Caribbean holiday.

A second image shows the Duke, wearing a pair of shorts, with his left arm around his wife as they walk along a beach

The pictures, which have been condemned by St James’s Palace, reportedly show Kate wearing a bikini and strolling on a beach on the island of Mustique with William.

They were published by Chi magazine, which last year provoked outrage from the Royal Family when it produced a 26-page spread showing the Duchess topless during a holiday in France.

On a website publicising Chi – owned by former Italian Prime Minister Silvio Berlusconi – Kate, who is about four months pregnant, is pictured on the magazine’s front cover in a blue bikini striding knee-high through the sea above the headline Kate & William in Mustique: The Belly Grows.

A second image shows the duke, wearing a pair of shorts, with his left arm around his wife as they walk along a beach.

A St James’s Palace spokesman said: “We are disappointed that photographs of the duke and duchess on a private holiday look likely to be published overseas.

“This is a clear breach of the couple’s right to privacy.”

The spokesman would not comment on whether William had been informed about the issue or if they were considering any form of legal action against the magazine.

The photographs were reportedly taken from a boat using a long-lens camera.

It is believed that the royal couple are still holidaying on Mustique and during their time on the island were reportedly joined by Kate’s family, parents Carole and Michael Middleton and her siblings James and Pippa.

Photographs of Pippa in a bikini are also being offered for sale, the Daily Mail said.

The publication by Chi comes less than six months after the printing of pictures showing the duchess wearing just a pair of bikini bottoms.

William was left visibly outraged by the intrusion into his wife’s privacy while they stayed at a private estate in southern France last summer.

France’s Closer magazine was the first publication to print the images in September last year and the duke and duchess later succeeded in getting an injunction from a French court stopping further pictures appearing in the title.

At the time, Chi’s editor Alfonso Signorini defended his decision to also publish the topless pictures, saying: “I am a director of a newspaper not a supermarket, I don’t sell artichokes and carrots, I sell photographic scoops.”

Australian magazine Woman’s Day also plans to publish the pictures of the duchess, Sky News reported.

Sky said the magazine was also expected to publish photographs of Kate’s sister Pippa in a bikini.

The magazine’s publication of the topless pictures last year against the couple’s wishes was condemned by British Prime Minister David Cameron.

It stirred memories of the world media’s relentless pursuit of William’s mother, Princess Diana, who died in a car crash in Paris in 1997 as she was being chased by paparazzi.

While magazines and websites in Europe have printed long-lens shots of the couple, Britain’s tabloid newspapers have so far held back.

The newspapers are fighting stricter regulation recommended by a judge-led inquiry into their tactics that uncovered illegal payments to public officials and phone-hacking to get stories.

The couple are expecting their first baby in July. The duchess was admitted to hospital in December suffering from an acute form of morning sickness.