The palace had come under mounting pressure to reveal the truth behind the image after international picture agencies withdrew it over claims that it had been manipulated.
Kate, in a statement released on social media, said this morning: "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."
The photograph of Kate and her children, taken by the Prince of Wales, was the first to be issued since the princess's abdominal surgery and was released by the palace to mark Mothering Sunday.
It is understood William and Kate wanted to offer an informal picture of the family together, with the princess making "minor adjustments".
It was withdrawn with a "Kill" notice by picture agencies last night and the UK's PA news agency this morning because of suspicions it had been manipulated. The controversy the palace's initial reluctance to comment served to fuel online speculation about Kate since her abdominal surgery in January.
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
'She handed over her house key I couldn't believe her trust in me, a complete stranger
As our final appeal total hits £3.46million we talk to a beneficiary of Refugees at Home a charity we are funding thanks to your amazing support
Make new and lasting changes
The start of a new year often inspires positive changes, and for those seeking to reclaim their mental health and wellbeing, Ibiza Calm provides a haven of transformation and healing
Feeling run down? Follow your gut feelings
Have you ever wondered why you feel constantly tired, experience brain fog or struggle with health issues like skin problems, pain or mood swings?
The kitchen is on fire but service is a washout
Chefs: duller than you think. Sporting rumours of delinquency still propagate—’shrooms at award shows, clingfilm mischief — but the naughty boys and girls are largely a lost breed.
Make room for what matters
The new year is here, and it's the perfect time to reset and refocus.
She stars in a Netflix mega hit and now Luciane Buchanan is playing a queen
It has been two years since action thriller The Night Agent landed on Netflix, but Luciane Buchanan, the breakout star of this twisty hit, still gets messages about it — ranging from the sublime to the ridiculous.
Will Levy pull the trigger on only answer to Spurs' woes?
Chairman would solve nothing by sacking Ange — he must spend
Why is the capital so full of charity muggers?
Pity the poor souls doing it but it's also a blight on our streets
A new year in the capital: start with healthy habits
Nutritional therapist and functional medicine practitioner Tracy Tredoux suggests ways to start the new year as you mean to go on
Ski's chicest, for before and après
This season's essential skiing guide for any budget