Italian magazine Chi has pledged to publish the pictures of a bikini-clad, pregnant, Kate, which are believed to show her strolling on a beach on the Caribbean island of Mustique with Prince William.
Meanwhile, the website of Chi's Milan-based publisher, Mondadori, claims that the magazine delivers stories and exclusive photographs 'in a tone that avoids scandal and gossip'.
The publisher adds that the weekly magazine 'also pays a great deal of attention to the quality of photography'.
St James's Palace yesterday issued a statement to reporters saying it was ‘disappointed' over the magazine's decision to publish the images, adding that it represented a ‘clear breach of the couple's right to privacy'.
Capturing such photographs in this country would break the UK press watchdog's current rules on privacy.
The Press Complaints Commission (PCC)'s Code of Conduct states that ‘it is unacceptable to photograph individuals in private places without their consent'.
The PCC adds that ‘private places are public or private property where there is a reasonable expectation of privacy'.
When approached by Amateur Photographer, a PCC spokesman today refused to say whether St James's Palace has contacted the watchdog regarding the images.
The spokesman said it was standard practice not to issue comment, for confidentiality reasons.
Last August, the PCC said Buckingham Palace had been in touch after photos of a naked Prince Harry emerged in Las Vegas.
The watchdog said the Palace had used the PCC's 'pre-publication services to pass on their concerns' to editors about potential publication of the pictures in British newspapers.
Last September, French magazine Closer was first to publish holiday snaps of a semi-naked Kate Middleton on holiday in France - images that were also published in Chi.