Joan Rivers has come under fire for poking fun at Adele's weight.

The acerbic comedienne referred to the singer's body whilst appearing on David Letterman's US chat show recently.

The veteran star, who is well known for her unrestrained humour, puffed out her face and stretched her arms when Letterman mentioned the singer's name.

Rivers was talking about attending the recent Oscars ceremony and the people she saw, adding:

"What is her song, 'Rolling in the Deep'? She should add fried chicken."

The audience seemed audibly taken aback by the jokes, who groaned and jeered.