British actors Daniel Radcliffe, Hugh Grant and Keira Knightley are amongst the celebrities that have signed up to perform on a special charity edition of TV talent show, 'American Idol'.

The show, called 'American Idol Gives Back', is a one-off event to raise money to help children and young people in extreme poverty in America and Africa.

Others that will be joining them include Forest Whitaker, Helena Bonham Carter, Borat Sagdiyev (aka Sasha Baron Cohen) and Mr Bean (Rowan Atkinson).

The actors will take to the stage alongside singers like Josh Groban, Michael Bublé, Annie Lennox, Pink and Gwen Stefani.

Television and comedy star Ellen DeGeneres will host the show.