Royal couple 'saddened' by Kate topless pix claim

"The incident, if true, turns the clock back 15 years," a royal source travelling with the couple in predominantly Muslim Malaysia told AFP, referring to the intense media attention on William's late mother Diana.

Diana died in a car crash while fleeing paparazzi in Paris in 1997.

(SEE ALSO: MSN Malaysia's Royal Visit Special)

France's Closer magazine said its latest edition would feature "the photos that the world can't wait to see; the Duchess of Cambridge topless on a guesthouse terrace".

The story was picked up in the British media on Friday, less than a month after the publication of naked pictures of William's brother Harry.

"Their royal highnesses were saddened to learn about the alleged photos," the royal source said.

 (SEE ALSO: Palace confirms Prince Harry nude photo scandal)

The monarchy was investigating the authenticity of the photos and will then "make a decision about what to do," the source added.

Britain's younger royals are touring the globe throughout 2012 as part of celebrations marking the 60-year reign of William's grandmother, Queen Elizabeth II.

They are now on a nine-day trip that started in Singapore, saw them arrive in Malaysia on Thursday, and which will move on this weekend to the Solomon Islands and later Tuvalu.

Visiting a hospice in the Malaysian capital Kuala Lumpur Thursday, Kate made her first comments on foreign soil, discussing care for disease sufferers in brief remarks as the British monarchy continues to ease her into her official role.

(SEE ALSO: Prince William and his wife Catherine arrive in Malaysia)

But the photo row risked casting a pall on the tour, which was meant to help introduce the couple overseas after their pomp-filled marriage last year that was watched around the world.

The royal couple dazzled thousands of cheering Malaysian fans on Friday in a public appearance where they were welcomed by a performance by practitioners of the Southeast Asian martial art known as silat and the rumble of traditional drums.

They arrived to wild cheers for the event, held at a park under the shadow of Kuala Lumpur's iconic Petronas twin towers in tropical heat that at one point had Kate complaining, "It's hot."

(SEE ALSO: Huge crowd greets the royal couple at KLCC Park)

They greeted a crowd of students and other fans who shoved floral bouquets upon Kate.

As the couple were chatting with the crowd, William at one point nimbly caught the falling sunglasses of a star-struck Michelle Marlow, 39.

"Chivalry isn't dead," swooned Marlow, who promised never to wash the glasses.

During a lunch Thursday with Prime Minister Najib Razak, the royal couple sampled durian -- the large, spiky fruit whose flesh is notorious for its pungent odour and which is known in Southeast Asia as the "king of fruits".

But at a lunch Friday with British and Malaysian business figures, William quipped: "For a start I would just like to say how delicious lunch was and how relieved I was that durian was not on the menu."

"Having tried it yesterday at the prime minister's lunch, I fear for the safety of the people I met thereafter," he said, causing the assembled crowd of hundreds of executives to erupt in laughter.