British actors Keira Knightley and Orlando Bloom pose for photographs after holding a press conference to promote their new film, Pirates Of The Carribean: Dead Man's Chest, at Claridges Hotel, in central London Tuesday July 4, 2006. (AP Photo/Stefan Rousseau,PA)

British actress Keira Knightley poses for photographs as she arrives for the European premiere of "Pirates of the Caribbean: Dead Man's Chest" at Leicester Square, central London, on July 3, 2006. The film is on general release in the UK and Ireland from July 6. REUTERS/Phil Noble (BRITAIN)

British actress Keira Knightley on Tuesday denied rumors she was suffering from the eating disorder anorexia.

Speaking a day after a revealing dress she wore at the London premiere of her latest film prompted questions about her weight, she added that she had a family history of the illness.

"It was really weird, they said that to me yesterday," the 21-year-old told a news conference, referring to the premiere of "Pirates of the Caribbean: Dead Man's Chest" in which she stars alongside Johnny Depp.

"They asked: 'How does it feel to be always called anorexic?' I had no idea that I was. I can safely say that I'm not.

"I've got a lot of experience with anorexia. It was in my family. My grandmother, and my great-grandmother suffered from it and I had a lot of friends at school who suffer from it so I don't think it's anything to be taken lightly."