(CNN) -- Two photographs of Madonna set to appear in a Christie's auction next month will probably sell for at least $10,000 each, according to estimates posted on the company's Web site.

One, a full-frontal nude black-and-white photograph of the singer, was taken in 1979 by celebrated American photographer Lee Friedlander for a series of nudes he was working on, said Milena Sales, a spokeswoman for the auction house.

Madonna was about 20 when the photograph, one of several, was taken.

A handful from the shoot appeared in Playboy magazine in 1985, Sales said. Christie's put price estimates for the photograph at $10,000 to $15,000.

The second photograph of Madonna was taken in the 1980s by Helmut Newton.

In the Newton photograph, which is in color, Madonna is wearing a short dress and black stockings with garters. The circumstances behind the photo shoot were not immediately clear.

The auction will take place in New York on February 12.