A series of steamy shots of Elle MacPherson and Cindy Crawford are going under the hammer in a Playboy auction later this month.
 
The sexy snaps feature the Aussie beauty completely nude in a set taken for Hugh Hefner's magazine in 1994, while Cindy Crawford can be seen cupping breasts in another racy image.
 
The pictures, along with a Marilyn Monroe photo, will be sold at New York's Christie's auction house on December 8 and are expected to fetch $4.5 million.
 
Hefner says, "We're paying tribute to our greatest contributors."

See more photos of Cindy here!

See more photos of Elle here!