Keira Knightley donating dress

Last week, actress Keira Knightley was criticized for looking too thin in the gold Gucci gown she wore to the premiere of her new movie 'Pirates of the Caribbean: Dead Man's Chest,' prompting rumors she had a weight problem. Knightley denied the allegations, and now the actress is giving the extravagant dress away to charity, according to Lifestyle Extra.

"I'd like to give it to charity for them to sell. It's not the kind of thing you can get away with wearing twice," the 21-year-old actress said.

This is the second time the star has donated one of her dresses away for a good cause. Earlier this year, she auctioned off the Vera Wang dress she wore to the 2006 Oscars on E-bay and she raised over ú4,000 for charity.

Currently, Knightley is starring in the 'Pirates of the Caribbean' sequel alongside Orlando Bloom and Johnny Depp. This past weekend, the movie broke box-office records in Britain and the United States with the most profitable opening days in history.