Pippa is said to have been told photographs illegally taken from her iCloud account are being offered to publications.
They are claimed to include pictures of Pippa fitted in a wedding dress and naked snaps of Mr Matthews as well as pictures of the Duke and Duchess of Cambridge. Around 3,000 images are believed to have been taken after the account was hacked.
Private messages sent by and to Pippa are also thought to have been stolen in the hack. It is understood representatives of the couple are set to contact police about the alleged attempt to sell the pictures.