Questions have been raised that the first picture of the Princess of Wales to be released after her abdominal surgery may have been manipulated before it was posted on social media by Kensington Palace.

The photo of Kate and her children, said by the palace to have been taken by the Prince of Wales in Windsor earlier this week, was posted to mark Mother’s Day.

In the post she said: “Thank you for your kind wishes and continued support over the last two months.

“Wishing everyone a Happy Mother’s Day. C.”

The picture shows Kate sitting in a chair with her arms around Princess Charlotte and Prince Louis, who are on either side of her, with Prince George standing behind, as all four smile at the camera.

The photograph was shared with media on Sunday but it was withdrawn by international picture agencies later the same day because of concerns that the image had been manipulated.

There was speculation that edits had been made to the left sleeve of Princess Charlotte’s cardigan, and other areas of the picture also raised concerns about possible manipulation.

Kensington Palace has declined to comment.

Confusion over the picture could fuel online conspiracies about Kate which have been swirling on the internet since her surgery.

The photo of the princess is the first released since she was admitted to the London Clinic, the private hospital where the King underwent treatment for an enlarged prostate, for a planned operation on January 16.

Charles, 75, visited his daughter-in-law’s bedside after being admitted himself on January 26, the 11th day of Kate’s stay.

She was also visited by her husband, William.

Kate left the hospital on January 29, almost two weeks later, and returned to Adelaide Cottage in Windsor.

Details of the princess’s condition have not been disclosed but Kensington Palace previously said it was not cancer-related and that Kate wished her personal medical information to remain private.

The 42-year-old future queen was last pictured in public during a Christmas Day walk in Sandringham, Norfolk.

Kate is not expected to return to official duties until after Easter, and William, 41, had temporarily stepped back from his royal role to juggle caring for her and their children.

He carried out his first public engagements since her surgery in early February.

Earlier this month the Army was forced into an embarrassing about-turn after suggesting Kate would attend Trooping the Colour on June 8.

Tickets were being sold for the event, with Kate expected to attend in her role as Colonel of the Irish Guards, the regiment which is trooping its colour this year,

However, it is understood the Army did not seek approval from Kensington Palace before publishing the page, and the website was subsequently updated to remove the reference to her.

A spokesperson for the PA news agency said it had not killed the picture on its service, but was seeking urgent clarification from Kensington Palace about the concerns raised about manipulation.