Tim Burton finds it "easy" to direct girlfriend Helena Bonham Carter.

The filmmaker has worked with his partner on several projects, after meeting on the set of 'Planet of the Apes', but he insists it's not hard because Helena is such a good actress.

He said: "It's quite easy. The fact is, before I met her, she'd done lots of things. She's very secure in what she does. There's no conflict. She's the most secure actress I've ever met. So there are no problems - yet!"

However, Tim - who has two children, Billy, eight, and four-year-old Nell, with Helena - says when he cast her in 'Sweeney Todd: The Demon Barber of Fleet Street' he was very harsh during her audition as he didn't want to be accused of favouritism.

He added to Total Film magazine: "When we did 'Sweeney Todd' I didn't want to seem like I was giving the job to my girlfriend or anything. I was probably harder on her for that reason - I just wanted to make sure that she was really, really right for it."