The Daily Mail said that the former model, whose divorce from the former Beatles star has been beset with controversy, claims that unbeknown to her McCartney had more than $19 million in paintings removed from his East Sussex estate where she is staying.
The 38-year-old recently arrived back to the estate and was so shocked to find the artwork missing, she originally contacted area police to report a possible burglary.
"Heather is staggered," a friend of Mills confessed to the paper. "Several pictures, including Renoirs and Picassos which have been hanging on the walls for months, have been taken. Photos of her and Beatrice have also vanished."
"Heather can't believe things have got this bad," the unidentified friend added. "She's not fussed about the pictures. She is more concerned about the family photos that have been taken."
Celebrity Breakups and divorces of 2014 [PHOTOS]