The picture agency says it has added an editor's note to the image, which was shared by Kensington Palace in April 2023 on what would have been the late Queen's 97th birthday.

The palace shared the picture on 21 April last year, saying it was taken by the Princess of Wales at Balmoral in the summer of 2022.

In a statement, Getty said: "Getty Images can confirm that in accordance with its editorial policy it has placed an editor's note on a handout image stating the image has been digitally enhanced at source."

The decision by Getty follows picture agencies issuing a "kill notice" for a photo released on Mother's Day by the Princess of Wales. She later admitted to editing the image.

A photo forensics expert has told Sky News the alterations made to the image featuring the late Queen are a better editing job than Kate's Mother's Day photo - and might not have been made by the same graphic artist.

There are at least three vertical splices and a variation in the number of light reflections in their eyes, they said.

Major international picture agencies pulled the Mother's Day photograph amid concerns "the source had manipulated the image" after people cited several peculiarities, including issues with Princess Charlotte's sleeve, the uneven pattern on Prince Louis's jumper and the window frame behind Prince George.

It was supposed to be a family photo to mark Mother's Day - and to quell speculation about Kate's health and whereabouts.

But the release of the picture of the Princess of Wales with her three children by Kensington Palace ended up triggering more conspiracy theories.

The 42-year-old future queen was admitted to the London Clinic for a planned abdominal surgery on 16 January.

She was last officially pictured on Christmas Day as she attended the Royal Family's annual church service in Sandringham, Norfolk.

However, several images of the princess have been published this month.

US celebrity news site TMZ published a picture of Kate wearing dark sunglasses and sitting in the passenger seat of a black Audi being driven by her mother, Carole Middleton, which it says was taken near Windsor Castle on 4 March.

A photo of her leaving Windsor in a car with Prince William as he was driven to the Commonwealth Day service at Westminster Abbey in London was published a week later.

Kate did not attend the service, but is understood to have had a private appointment.

Yesterday, footage of Kate and William was published by The Sun, which the newspaper said was taken on Saturday at Windsor Farm Shop, close to their Adelaide Cottage home in the grounds of Windsor Castle.

It showed a smiling Kate walking alongside and chatting with her husband and carrying a large white bag.

The couple also spent Sunday morning watching their children taking part in a sports event, according to The Sun.

Read more from Sky News:
Trust in royals not dented by conspiracies, poll shows
Kate's doctored photo poses big questions of royals
What the data says about Kate's edited photo
A look back at Princess of Wales's photography

A spokesperson for Kate said she was "making good progress" when she returned home to Windsor following her operation.

The London Clinic is the private hospital where the King underwent treatment for an enlarged prostate in the new year.

Charles, 75, visited his daughter-in-law's bedside after being admitted himself on 26 January.

Kate is not expected to return to official royal duties until after Easter.