Nude photos of Gisele Bundchen and Kate Moss

They are among fashion's highest paid models, paid thousands to model designer clothes.

But in these rarely seen photos, the only outfit they needed to show off was their birthday suits.

Kate Moss and Gisele Bundchen are among several celebrities featured in a stunning collection of photography which is set to go under the hammer Christie's auction house in New York.

Amazonian: Athletic Giselle Bundchen goes au natural with bronzed skin and tousled locks for this Irving Penn portrait which is part of an extensive private collection being auctioned off by Christie's New York, next month

Unspoilt: An innocent, unspoilt Kate Moss in a 1996 photographic portrait by Irving Penn

The tastefully shot nudes show a young, unspoilt Kate Moss, and an Amazonian looking Gisele Bundchen shot by photographer Irving Penn.

Kate's photo is expected to fetch $30-40,000 (£15-£20,000) at auction, as is Brazilian Gisele's.

The photographs are taken from collector Gert Elfering extensive collection which will be auctioned off at Christie's next month.

It's expected to fetch in excess of £2-3million.

For sale: The auction will take place at Christie's auction house in New York on April 10

Among the images on offer are portraits of 60s icon Brigitte Bardot and a reclining nude of American actress Lauren Hutton and a set of four psychedelic Beatles portraits all by celebrated fashion photographer Richard Avedon.

Elfering, 49, one of the world's foremost collectors of 20th-century photography, owns iconic prints by such greats as Helmut Newton, Avedon, Man Ray, Robert Mapplethorpe, Guy Bourdin, Cindy Sherman, Diane Arbus and legendary photographer Horst P. Horst.

He first encountered the work of Horst in the early Eighties when the then 25-year-old German walked into Hamilton's Gallery while vacationing in London.

Reclining: American actress Lauren Hutton is part of the collection which is expected to fetch £2-3million at Christie's New York auction house

Elfering recalled he was instantly taken with the dramatic portraits but was unable to afford even a single print.

Instead, he left with a book and a poster. In 1998 he acquired the complete Horst archive.

"It just shows," says Elfering, "how times can change."

"I started with a book and a poster, then moved on to smaller prints, then more expensive ones, and finally the estate," says Elfering.

And now he's letting most of it go - 135 lots - in a sale in New York on April 10, 2008.

But not before giving the public a chance to see them one more time.