Bonham-Carter joins Sweeney movie

Bonham-Carter is the partner of Sweeney Todd director Tim Burton

British actress Helena Bonham-Carter is to star alongside Johnny Depp in a film version of Stephen Sondheim's musical Sweeney Todd.

The Oscar-nominated star, 40, will play Mrs Lovett, a murderess who dispenses her victims' bodies in meat pies.

Angela Lansbury originated the role in a 1979 Broadway production of the musical, which won eight Tony awards.

Sweeney Todd will be Bonham-Carter's fifth film outing with director Tim Burton, who is also her partner.

The couple have previously collaborated on Planet of the Apes, Big Fish and Corpse Bride.

Their adaptation of Roald Dahl's Charlie and the Chocolate Factory, which also starred Depp, made more than $470m (£248m) worldwide last year.

Both Bonham-Carter and Depp will perform their own songs in Sweeney Todd, which is due to start filming in early 2007.

Depp, 43, takes the title role as the legendary London barber who murders his customers by slitting their throats.

He forms an amorous relationship with Mrs Lovett, who helps him dispose of his victims' bodies by turning them into meat pies.

Bonham-Carter has recently been filming the latest Harry Potter movie, in which she plays the witch Bellatrix Lestrange.