Pupils from Haberdashers' Aske's Hatcham College, New Cross, were asked to don costumes and sing as the Hogwarts choir to accompany the launch of the Harry Potter and the Prison of Azkaban DVD on November 18.

Director of music at the college John Skinner was called by the film's public relations firm asking for 25 youngsters aged 13 and 14 for the Harry Potter event after the choir performed at the Royal Opera House in the Greek Passion by Martinu.

He said: "The children thought it was great being dressed in Hogwarts stuff. It was superb fun."