Keira Knightley strips for her new film - only to have her breasts belittled.

The 21-year-old star gets naked in new movie Silk, but her character's husband says her breasts are "small" and "like a child's".

A source said: "For all the people excited to see Keira, yes, you do see her topless.

"She is nude in a couple of scenes, once during a love scene and another when she leans over her husband with her gown gaping open and he remarks that her breasts are small and like a little girl's."

Keira plays Helene, the wife of 19th century silkworm smuggler Herve who is in love with a Japanese baron's concubine.

The Pirates of the Caribbean actress has flashed flesh in previous films, including The Jacket, Domino and The Hole - in which she exposed her breasts.