Roberts returns to acting - for free

Julia Roberts is to make her acting return after giving birth to twins - for free.

The Pretty Woman actress with join Paul McCartney and Robin Williams at a star-studded benefit for Paul Newman's Hole in the Wall Camps - the world's largest association of camps for children with serious illnesses.

The Lincoln Center's Avery Fisher Hall event in New York will feature a performance which will be co-produced by veteran entertainer Lou Adler.

The full details of the event are being kept a closely-guarded secret, but Roberts is expected to team up with Newman for one of the evening's dramatic turns.