Editor's Note, 6:50 p.m. ET: This story has been updated and the original photo was removed after multiple photo outlets advised news agencies to discontinue use of the image released by the royal family.
The first photo of Catherine, the Princess of Wales, since her abdominal surgery nearly two months ago was released Sunday along with a statement thanking the public for its support, but within hours major photo agencies issued notices advising outlets to no longer distribute the image, saying that it appeared to have been "manipulated at the source."
The photo of her in a chair surrounded by her three children was credited to her husband, William, Prince of Wales and heir to the throne, and was said to be taken earlier in the week in Windsor.
“Thank you for your kind wishes and continued support over the last two months,” Catherine said on social media. “Wishing everyone a Happy Mother’s Day.”
The Princess of Wales apologized in a statement Monday morning, acknowledging she edited the family photo.
"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. I hope everyone celebrating had a very happy Mother’s Day," a statement posted on the Prince and Princess of Wales social media accounts said.
The photo's release followed weeks of wild speculation on social media about her whereabouts since she left a hospital on Jan. 29 after a nearly two-week stay following planned surgery. She hadn't been seen publicly since Christmas Day.
In addition to being posted on several of the royal family's social media accounts, the photo was released through the United Kingdom's Press Association, and internationally through the photo agencies AFP, Reuters and the Associated Press.
Later Sunday, AP, Reuters and AFP all said media outlets should no longer use the image.
"The Associated Press initially published the photo, which was issued by Kensington Palace," the agency said in a statement to NBC News. "The AP later retracted the image because at closer inspection, it appears that the source had manipulated the image in a way that did not meet AP's photo standards. The photo shows an inconsistency in the alignment of Princess Charlotte's left hand."
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Reuters sent an advisory to subscribers that the image "has been withdrawn following a post-publication review."
The royal family has been under more scrutiny than usual in recent weeks, because both Catherine and King Charles III can’t carry out their usual public duties because of health problems.
Royal officials say Charles is undergoing treatment for an unspecified form of cancer, which was discovered during treatment for an enlarged prostate. The monarch has canceled all his public engagements while he receives treatment, though he's been photographed walking to church and meeting privately with government officials and dignitaries.
Catherine, 42, underwent surgery on Jan. 16 and her condition and the reason for the surgery have not been revealed. However, Kensington Palace, Prince William and Catherine’s office, said it was not cancer-related.
Although the palace initially said it would only provide significant updates and that she would not return to royal duties before Easter — March 31 this year — it followed up with a statement last month amid the rumors and conspiracy theories by saying she was doing well and reiterating its previous statement.
“Kensington Palace made it clear in January the timelines of the princess’ recovery and we’d only be providing significant updates,” the palace said on Feb. 29. “That guidance stands.”
At the time, royal aides told The Sun newspaper: “We’ve seen the madness of social media and that is not going to change our strategy. There has been much on social media but the Princess has a right to privacy and asks the public to respect that.”
Further questions were raised last week when the British military appeared to jump the gun in announcing Catherine would attend a Trooping the Color ceremony in June, apparently without consulting palace officials.
The appearance would have been her first major official duty since the surgery but Kensington Palace didn't confirm any scheduled public events for Catherine. It’s up to palace officials, not government departments, to announce and confirm the royals’ attendance at events.
The army later removed the reference to her attendance.
British media reported that the army did not seek approval from Kensington Palace before publishing details about Catherine's appearance in June, and announced the event based on the expectation that Catherine, in her role as Colonel of the Irish Guards, would inspect the troops this year at the annual military ceremony.
The Associated Press contributed to this report.