Celebrities shed their clothes - for a good cause

You can. A collection of clothing and accessories that promises to be the biggest sale of designer goods in the world goes online today.

Members of the world's fashion elite such as Stella McCartney, Dolce & Gabbana and Tommy Hilfiger have donated sample dresses, sweaters, shoes, handbags, books, perfumes and even furniture for a four-week auction for HIV/Aids charities.

Some of the garments on sale have been worn by Hollywood stars for fashion shoots or red-carpet events. Others, such as the suede boots by Diane von Furstenberg, are one-offs never commercially produced.

The Council of Fashion Designers of America Foundation is behind the 7th On Sale Online, which is being launched at a celebrity gala in New York tonight. Designers hope the sale will repeat the success of earlier 7th On Sales in 1990, 1992 and 1995, which raised $11m (£6.3m) for Aids/HIV causes. The proceeds of this year's - the first online auction - will go towards education and prevention.

The organisers read like a roll-call of the rich and powerful in fashion: Domenico Dolce, Stefano Gabbana, Ralph Lauren, Marc Jacobs and Donna Karan and Anna Wintour. Among the designers giving away their products are Prada, Versace, Dior, Burberry, Moschino, Alexander McQueen and Calvin Klein.

Kenneth Cole, one of the chairmen, lamented that more than 20 years after its discovery no cure had been found for Aids. "Forty-two million people are infected with HIV/Aids and the largest statistic of all is '0'. That is the number of people who have been cured," the designer said.

"To reach as many people as possible in this fight, the use of the internet was a logical and uncircumventable conclusion."

On Monday, a preliminary sale of nine "fashion adventures" began, offering the chance to celebrate the reinvention of the iconic Playboy costume with the designer Roberto Cavalli in Las Vegas or stay in a Brioni-designed suite at the Four Seasons in Milan.

Among the garments for sale are a tulle halter dress by BCBG Max Azria worn by Keira Knightley (valued at $15,000), a Carolina Herrera silk gown modelled by Zellweger ($5,490) and a Donna Karan jersey dress worn by Susan Sarandon. There are also cheaper items such as a Marc Jacobs men's cashmere turtleneck ($495) and a Gerard Yosca pair of chandelier earrings ($300). Ralph Lauren alone has donated 700 samples for sale, including a black alligator weekend bag ($15,000) and an Edwardian-style upholstered bed with bedding, pillows and a fox throw. The shoemaker Manolo Blahnik has donated some of his creations.

The sale can be found at: www.ebay.com/7thonsale