The photo in question, released on social media by the Kensington Palace. Photo: Kensington Palace / via X
By Emma Harrison and Sean Coughlan, BBC News
The Princess of Wales has apologised "for any confusion" after she said she edited a Mother's Day photograph of her and her children.
Her statement was posted on Kensington Palace social media after five agencies retracted it over editing concerns.
"Like many amateur photographers, I do occasionally experiment with editing," Catherine said.
The image, taken by the Prince of Wales, was the first of Catherine to be released since her surgery in January.
PA, Getty Images, AFP, Associated Press (AP) and Reuters had removed the image. AP noted an "inconsistency in alignment of Princess Charlotte's left hand".
In her statement on X, formerly Twitter, Catherine said: "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. C."
The apology, posted to social media, comes from the official account of the Prince and Princess of Wales, but it has the personal sign off of "C", for Catherine.
She is taking responsibility for the changes to the photograph, rather than her husband Prince William, who took the photo, or any of the wider team around the royal couple.
According to royal sources, there were "minor adjustments" made by the Princess of Wales to the picture that was then posted online by Kensington Palace.
Kensington Palace said it would not be reissuing the original unedited photograph of Catherine and her children.
We know the photograph was edited, but some basic information about the image remains unknown - such as when exactly it was taken, what was changed or whether it was a composite of a number of pictures.
The photograph shows the princess sitting down, surrounded by Princess Charlotte, Prince Louis and Prince George, the latter wrapping his arms around her.
It was the first official photo of the Princess of Wales since her abdominal surgery two months ago. Since then she has stayed out of the public eye.
The image was posted with a message from Catherine which said: "Thank you for your kind wishes and continued support over the last two months.
"Wishing everyone a Happy Mother's Day."
The photo was only intended as an "amateur, family photograph" released to mark Mother's Day, say royal sources.
The implication is that this was not a piece of professional manipulation, but some tidying up of a picture capturing a family moment.
Except that this was not just a personal picture, it was going to be shared with the world, against a background in which it would inevitably be seen as an attempt to stop the speculation and conspiracy theories about Catherine, as she recovers from an operation.
'Raising more questions'
Instead of providing an answer to such rumours it inadvertently ended up raising more questions.
The photo will also lead to discussions about how media outlets should use images or social media clips which are produced without any independent journalists being involved.
Although most public royal events will have professional photographers and press representatives, this was seen as a private moment, captured by the family themselves, as the princess recovers.
The only previous photo of the princess since her operation was a paparazzi shot, which was not used by UK news organisations because of concerns about breaches of privacy.
There have been previous examples of Kensington Palace putting out video footage without any external journalists being present, including a visit by the Princess of Wales to a "baby bank" helping disadvantaged families.
The Mother's Day image was included on the front pages of several national newspapers and websites, including BBC News, and used on TV news bulletins - again including the BBC.
In order to use the new photo as quickly as possible, the BBC took the one used by Kensington Palace on their social media accounts.
Five photo agencies retracted the image over concerns it had been "manipulated". The Associated Press issued a "kill notification" - an industry term used to make a retraction - late on Sunday, saying: "At closer inspection it appears that the source has manipulated the image. No replacement photo will be sent."
Reuters said it too had withdrawn the image "following a post-publication review" and AFP also issued a "mandatory kill notice".
Getty Images became the fourth organisation to retract the photograph. And PA said later on Monday it too had retracted the image, based on there being no clarification from Kensington Palace.
Most news organisations follow their own strict guidelines on the use of manipulated photographs, only using them when accompanied by an explanation that the image has been changed from the original.
News agencies, such as AP, therefore make a commitment to their clients that their photos are accurate and not digitally manipulated.
AP's rules only allow "minor adjustments" in certain circumstances, including cropping and toning and colour adjustments, as well as the removal of dust on camera sensors. It says changes in density, contrast, colour and saturation levels "that substantially alter the original scene" are not acceptable.
Later on Monday, the Princess of Wales was seen in public with William, as the pair left Windsor in a car.
Kensington Palace said the Prince of Wales was being driven to the Commonwealth Day service at London's Westminster Abbey.
Catherine is not attending the service but is understood to have a private appointment.
A short while later, William was seen alongside Queen Camilla at the service celebrating the Commonwealth.
Some 56 countries make up the Commonwealth of Nations - this year marking its 75th anniversary - the majority of which are former British Empire territories of which the King is still head of state.
Charles did not attend the service, due to his treatment for an unspecified cancer, but he pre-recorded a video message that was played to the 2000 guests.
Catherine, 42, spent 13 nights at the London Clinic, near Regent's Park in central London, following the surgery.
Prince William came to see his wife during her stay and she was also visited by the King before he had his own treatment there.
The Palace has shared few details about her condition, which has garnered significant social media speculation, but has said it is not cancer-related.
The team supporting the princess as she recovers is small and limited to those closest to her.
At the time of her stay, the Palace said the princess wanted her personal medical information to remain private, adding that she wanted to "maintain as much normality for her children as possible".
The Palace said it would only provide updates on her recovery when there was significant new information to share.
- This story was first published by the BBC