SYDNEY - One of Rupert Murdoch's Australian newspapers on Wednesday published a picture showing the bare bottom of Prince William's wife Kate, refusing to follow a "ridiculous" ban imposed by the British media.

The image was taken during the royal couple's hugely successful tour of Australia in April when they showed off their infant son George, and was run in the Sydney Daily Telegraph a day after it appeared in German tabloid Bild.

It shows the Duchess of Cambridge's summer dress lifted by a gust of wind when the royal couple got out of a helicopter in the Blue Mountains, 80 kilometres west of Sydney.

The Daily Telegraph said British newspapers had refused to run the photo out of respect to the royals, but in a comment piece said this was "an antiquated code of etiquette".

"It seems a bit ridiculous to expect the rest of the world's media to follow suit, particularly in a world in which flesh and commercialism go hand in hand," said Telegraph social writer Annette Sharp.

Ms Diane Morel, a Blue Mountains local, took the photo and almost deleted it before realising what she had captured. "It wasn't until I got home and I popped my camera card into the computer that I realised what I had captured," the 47-year-old told the newspaper, vowing to donate any money raised from the photo's sale to a bushfire relief fund.

During their tour, the royal couple met survivors and toured the scene of devastating Australian bushfires last year that destroyed more than 200 homes. In 2012, French magazine Closer provoked outrage among the royals and sections of the British press when it published paparazzi photos of a topless Kate.