Pictures of the Duchess of Cambridge and her children, Prince George and Princess Charlotte, are reportedly among 3,000 images stolen from Pippa Middleton by computer hackers.
The images, taken from an iCloud account belonging to Kate's sister and former bridesmaid, were offered to reporters by an anonymous seller via WhatsApp, The Daily Mail reported.
The paper said that the images offered included some of the royal children as well as wedding dresses and parties, with the seller wanting to sell in the US because of UK privacy laws.
The alleged theft comes two years after a host of celebrities, including Hollywood star Jennifer Lawrence, fell victim to a hacker attack on the iCloud - which stores private photos from phones and computers online - which saw images posted online.
In July it was announced that Miss Middleton would marry her financier boyfriend, James Matthews in a society wedding in 2017, with William and Kate saying they were a "wonderful couple".
Hedge fund boss Mr Matthews got down on bended knee during a trip to the Lake District after they had dated for less than a year.