Los Angeles  - A nude picture of Madonna when she was a struggling dancer in 1979 has sold for 37,000 dollars at auction - more than double the 15,000 dollars it was expected to fetch, Christie's auction house said Friday.

The buyer was identified as a European collector.

The picture, was taken by Lee Friedlander, who found then 20-year- old Madonna after placing an ad in a local paper. The explicit black- and-white picture and six others from the session appeared in a 1985 issue of Playboy.

Another risque photograph of Madonna by Helmut Newton sold for 18,750 dollars at the auction. The image, which shows Madonna in lingerie next to a kneeling man, had been expected to fetch 15,000 dollars. (dpa)