Rachel Weisz admits it can be uncomfortable appearing naked in a movie.

The 42-year-old actress used to feel anxious stripping off on set until she was helped get over her insecurities by Bernardo Betrolucci when he directed her in 1996's 'Stealing Beauty'.

She told W magazine: ''It is difficult to feel comfortable when you're acting and you are naked. I was naked in my first movie ... and the director, Bernardo Bertolucci, sort of made me feel ridiculous even to be worrying about showing my breasts.''

As a result, the star felt she had lost all her inhibitions for her role in 'The Deep Blue Sea' last year, which focused on her character Hester Collyer's affair with Freddie Page (Tom Hiddleston).

Rachel revealed: ''My character has a passionate need for her lover. The director, Terence Davies, told me, 'Rachel, I would like you to lick his back.'

''My character needs to nourish herself through this man or she will perish. So I licked him. I was tempted to take a bite.''

The actress recently admitted she loved playing a ''bad girl'' on-screen in her new role as the Wicked Witch of the East in the upcoming 'Wizard of Oz' reboot 'Oz: The Great and Powerful'.

She added: ''I didn't do any research at all for this film - I just tapped into my own bad girl.

''I'm as bad as the next person, but that's the thing about real life - we have to control ourselves.''