Catherine, Princess of Wales, on Monday apologised and admitted to editing an official portrait of her released by the palace that prompted AFP and other agencies to withdraw the altered image.

Kate, 42, has not been seen in public since attending a Christmas Day church service, and underwent abdominal surgery in January, fuelling speculation about her health.

Her Kensington Palace office on Sunday sought to dispel rumours by distributing an official photograph said to have been taken by her husband Prince William of his wife with their three children.

But questions quickly emerged about the Mother's Day portrait of a smiling Kate, casually dressed and seated in a garden chair, surrounded by Prince George, Princess Charlotte and Prince Louis.

They included several inconsistencies such as the zip of Kate's jacket being misaligned in one place, while part of Princess Charlotte's sleeve is missing.

The eight-year-old princess's hair also ends abruptly on her shoulder.

After Britain's respected Press Association news agency joined the growing boycott, Kate issued a statement. "Like many amateur photographers, I do occasionally experiment with editing," she wrote.

"I wanted to express my apologies for any confusion the family photograph we shared yesterday caused."

British media outlets quoted unnamed royal sources as saying that Kate had made "minor adjustments" to the picture.

Kensington Palace, however, said it would not republish the original, unedited photo.

 'Damaging' 

AFP, Getty, the Associated Press (AP) and Reuters all have policies about distributing manipulated images. They initially published the photo but pulled it late Sunday.

They decided after consultation that the modifications were "in violation of the ethical standards of the profession", said AFP's deputy news director in charge of photo, Eric Baradat.

"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," he added.

Many commentators suggested the furore cast fresh doubt on royal reassurances about Kate's health and recuperation.

Peter Hunt, a former BBC royal correspondent, said the situation was "damaging" for the family. "They knew there would be intense interest in any picture they released of Kate," he said.

"Their challenge is that people will now question whether they can be trusted and believed when they next issue a health update."

Graham Smith, who heads the Republic pressure group calling for an elected head of state, added: "It's quite simple. Don't use their own photos. It's PR, not news."

Laura Clancy, a media lecturer at Lancaster University in northwest England, said the situation highlighted the difficulties in modern media management.

British media outlets, often frustrated by palace stonewalling, have tended not to question official royal information, she added.

"The issue they've had is social media, where people can question and talk about it, and there's news outlets around the world who don't stick to that line and will ask questions," she told AFP.

The news agencies, by pulling the photo, forced the palace to react, she added.

 'Support' 

British media reported that Kate was seen travelling with William, 41, to central London, where he attended the annual Commonwealth Day celebrations with other senior royals.

The intense interest in Kate's well-being and her whereabouts stems from William being next in line to the throne currently occupied by his father, King Charles III.

Earlier this month, a snatched photograph said to have been of Kate, wearing sunglasses while being driven by her mother, were published on the celebrity news site TMZ.

But that, too, failed to dampen conspiracy theories online.

Sunday's contentious photograph overshadowed the Commonwealth Day event, even without the king in attendance as he undergoes treatment for cancer.

In a video message, the 75-year-old British head of state promised to serve the 56-nation grouping that he leads "to the best of my ability".

Charles has only been king and British head of state since the death of his mother Queen Elizabeth II in September 2022.

His wife, Queen Camilla, 76, has since stepped up to take the lead as the royals' most senior figure at public events.

The announcement about Kate's admission to hospital on January 16 came just before a separate statement revealing that Charles had a benign enlarged prostate, and later an unrelated cancer.

The unspecified cancer diagnosis has forced him to cancel public engagements, barring some official meetings.

But his absence, and that of Kate and William, have prompted questions about a power vacuum.