The magazine, Closer, has already published a teaser photo on its Web site showing Middleton in the process of removing her bikini top.
Kate Middleton’s sister, Pippa was photographed topless while cruising on a yacht with the royal couple who were not married at that time.
The pictures were taken while Kate was on holiday with husband, Prince William, in Provence in France last week, according to London’s Daily Mail.
The royal couple was staying at a chateau owned by Lord Linley, the Queen’s nephew, before they took off on their Diamond Jubilee tour of south east Asia and the South Pacific on behalf of the Queen, according to the tabloid.
More on Pippa and Kate Middleton
How the photographer could have gotten close enough to take the photos remains a mystery. The Chateau D’Aulet is set amid 640 acres of rolling countryside, suggesting the photos may have been taken by one of the household staff.
The Duchess was apparently snapped by a paparazzi while lounging around the chateau’s pool.
The incident comes after Prince Harry was photographed cavorting with naked girls at a party in his hotel suite in Las Vegas. The photos were published by gossip Web site TMZ in the United States, where press protections are stronger.
Closer is France’s largest celebrity magazine. The photos will also appear on the magazine’s Web site.