Britain's Duchess of Cambridge is said to be "saddened" by news a French magazine plans to publish topless pictures of her.

The royal enjoyed a holiday in Provence last week with her husband Prince William, and long-lens shots of the brunette beauty were allegedly taken beside a private swimming pool.

French magazine Closer - which plans to publish the images today - are reportedly expected to be contacted by palace officials asking them to "consider all options" if the pictures are proved genuine.

Catherine and William are currently on their fourth day of their nine-day Far East tour and are said to be "saddened" by the breach of privacy.

“This is disappointing, saddening and turns the clock back 15 years. We have always maintained the position that the duke and duchess deserve their privacy, not least when they are on holiday in their own swimming pool," a royal source told British newspaper The Daily Telegraph.

The duke and duchess were first told about the images at 5am on Friday local time in Kuala Lumpur by aides who were travelling with them.

The couple - who married in April last year - were shown teaser images on Closer magazine's website, with the accompanying headline: “Oh My God! Photos that will go around the world… the future Queen of England as you’ve never seen her before… and as you will never see her again!”