The UK edition of fashion magazine Grazia has admitted that it slimmed down the waist of the Duchess of Cambridge, Catherine, by digitally altering an image from her wedding day, when she was dressed in an Alexander McQueen gown.

The cover picture appeared during the May 9, 2011 weekly edition of the magazine of what appeared to be an "impossibly thin" Duchess standing alone with a bouquet of flowers.

Following a complaint to the Press Complaints Commission, Grazia explained how the image had been altered to remove the arm of Prince William so that the Duchess could be featured on the cover alone.

"This involved mirroring one of the Duchess's arms and an inadvertent result of the change was the slimming of her waist," the Press Complaints Commission stated.

"We would like to reassure all our readers that we did not purposely make any alternations to the Duchess of Cambridge's image to make her appear slimmer, and we are sorry if this process gave that impression. Grazia takes the issue of women's body image very seriously and we would never 'slim down' a picture of a female role model," the letter issued by Grazia to the Press Complaints Commission explained.

Earlier, there have been similar instances of a digitally altered image of Kate Winslet by GQ in 2003 where the magazine admitted the digital lengthening of the actress' legs.