LONDON — The Princess of Wales, Catherine Middleton, apologized Monday for “confusion” caused by her editing of a family photo released by the palace — a photo of her with her children that was intended to calm concern and speculation about the princess’s health, but had the opposite effect.

Five major news agencies, including the Associated Press, withdrew the image over concerns about digital manipulation.

That sent the online rumor mill, already filled with speculation over over Catherine’s recent surgery and recuperation, into overdrive.

In a post on social media, the princess said that “like many amateur photographers, I do occasionally experiment with editing.”

“I wanted to express my apologies for any confusion the family photograph we shared yesterday caused,” the post said.

The palace said the photo was taken by Prince William. Issued by Kensington Palace on Sunday to mark Mother’s Day in Britain, it was the first official photo of Kate since her abdominal surgery nearly two months ago.

“Thank you for your kind wishes and continued support over the last two months,” the princess said on social media. “Wishing everyone a Happy Mother’s Day.”

AP initially published the photo. While there was no suggestion the photo was fake, AP retracted it because closer inspection revealed the source had manipulated the image in a way that did not meet AP’s photo standards. For instance, the photo shows an inconsistency in the alignment of Princess Charlotte’s left hand.