The modified official photo of Catherine, Princess of Wales, and her children did not respect "the ethical standards of the profession", said Agence France-Presse (AFP), which withdrew the portrait.
The global news agency was one of several leading outlets, including the Associated Press, Reuters, Getty and Britain's domestic Press Association to "kill" the image, withdrawing it from distribution to clients.
Analysis of the Mother's Day image, released on Sunday by Kate's Kensington Palace office, highlighted "several inconsistencies in alignments", AFP said.
They include:
- Misalignment of Kate's zip, and a dark visible line below
- A missing part of Princess Charlotte's sleeve
- Charlotte's hair ending abruptly on her shoulder.
The image, said to have been taken by Kate's husband and heir to the throne Prince William last week, was released after weeks of rumours about her health, after she underwent abdominal surgery in January.
The 42-year-old princess has not been seen in public since a Christmas Day church service on December 25, and is not expected to make a return to official royal duties until at least next month.
Eric Baradat, AFP's deputy news director in charge of photo, said the agency's photo editors in London consulted with their counterparts at other news agencies on Sunday about alterations to the photo.
They decided that the modifications were "in violation of the ethical standards of the profession", he said.
"As a result, they collectively agreed to remove the photo from their distribution platforms," Baradat added.
"From the outset, AFP had duly noted that it was distributing a photo provided by a third-party institution.
"AFP felt compelled to remove the photo to preserve the trust of its subscribers and maintain transparency to the public, especially in a society where manipulated images are prevalent."
Keen photographer Kate has taken several official portraits of her family that were distributed by the palace to media outlets.
"Like many amateur photographers, I do occasionally experiment with editing," she said on Monday, after the multiple "kill" notices further fuelled the speculation about her health and whereabouts.
"I wanted to express my apologies for any confusion the family photograph we shared yesterday caused," she added in a statement.
