Photo verification expert reacts to Kate Middleton's edited Mother's Day picture

Kate Middleton's Mother's Day celebrations were marred by controversy Sunday after a family photo she shared was accused of being manipulated with digital editing.

The photo, released by Kensington Palace, was picked up by several international news agencies and later retracted. The Associated Press said it appeared "the source had manipulated the image in a way that did not meet AP's photo standards."

PA Media Group, a news agency in the United Kingdom, also retracted the image.

The family photo shows Middleton and her three children -- Prince George, 10, Princess Charlotte, 8, and Prince Louis, 5 -- and was taken at their home in Windsor. Kate credited her husband, William, the Prince of Wales, as the photographer.

Hany Farid, a University of California, Berkeley, computer science professor who specializes in detecting manipulated images, told ABC News that the photo appears to have been manipulated but not entirely fabricated.

"I think it is unlikely that this is anything more than a relatively minor photo manipulation," Farid said.

Farid added, "There is no evidence that this image is entirely AI-generated."

Farid pointed out a visual irregularity around the left hand of Princess Charlotte has evidence of manipulation.

Editors at the AP said the photo “shows an inconsistency in the alignment" of the young royal's hand.

The sleeve on Charlotte's red sweater appeared to be digitally cropped, which resulted in her wrist looking slightly bent.

"You see what looks like traces of manipulation," Farid explained. "I think most likely it is either some bad Photoshop to, for example, remove a stain on the sweater, or is the result of on-camera photo compositing that combines multiple photos together to get a photo where everyone is smiling."

Farid noted that photo compositing where the subjects move between successive images can cause the type of "ghosting" seen on Charlotte's sweater.

The Princess of Wales released a statement on Monday, taking responsibility for the edited photo and apologizing for any "confusion" those alterations caused.

"Like many amateur photographers, I do occasionally experiment with editing," Middleton said in a statement. "I wanted to express my apologies for any confusion the family photograph we shared yesterday caused. I hope everyone celebrating had a very happy Mother's Day."

The photo was the first official image released of Middleton following her abdominal surgery on January 16.

Kensington Palace said it would not reissue the original unedited photograph of Kate and her children.