Keira Knightley " too shy to talk to her fans".

Keira Knightley has revealed that she intentionally dresses down while out in public because she's too shy to talk to her fans.

The star also admitted that she struggles with fame because she is naturally 'very shy' and feels uncomfortable when people stop her in the street.

Knightley always wears her scruffiest clothes when out and about in a bid to go unnoticed, and avoids showbiz parties to maintain her low profile, but the 25-year-old fears her tactics aren''t working.

"I think it (fame) broke something in me. I was told very early on that if I didn''t go out to openings and parties and events I would be left alone. I didn''t, and they still didn''t leave me alone," the Daily Star quoted Knightly as telling Vogue magazine.

"I knew it was part of the deal in the life I had signed up to, but the fear of it has never left me. I''m still not good at being recognized. I wear scruffy clothes and hats and keep my head well down. I''m sure people must think I''m a complete b**ch, but I''m just very shy," she added.