Pictures allegedly taken from a newly discovered 8-mm version of a film, purportedly showing Marilyn Monroe having sex when she was still an underage actress known as Norma Jean Baker, are shown by Spain's memorabilia collector Mikel Barsa in Buenos Aires, Argentina, July 20, 2011. Barsa plans to auction the film but an expert says the actress in the film is someone else, considerably heavier and less feminine than the legendary film star.

BUENOS AIRES, Argentina - A Spanish collector who generated a scandal in 1997 when he screened 16-mm film purportedly showing an underage Marilyn Monroe having sex is creating another buzz after announcing plans to auction what he claims is a newly discovered 8-mm version of the film.

Collector Mikel Barsa is seeking at least $500,000 for the sexually explicit 6-1/2 minute, grainy black-and-white film, which he says was made before 1947, when Monroe was not yet 21 and was known as Norma Jean Baker.

An expert on the actress, however, says the actress in the film is someone else.

"If you look at the face obviously you see some resemblances very clearly right away," says Scott Fortner, who has a sizeable collection of Monroe memorabilia.

PHOTOS: Marilyn Monroe

But, Fortner adds, "For me if you look at the chin line, at the jaw line, at the teeth of the woman in the film and compare that to Marilyn you can clearly make some distinctions."

The face of the woman in the film does appear considerably different from the Monroe who emerged later as a star, but more similar to the Monroe seen in one of her first movies, 1949's "Love Happy," which shows the actress before she lost weight, added a beauty spot on her left cheek and became one of Hollywood's most enduring stars.

"The Marilyn that everybody knows is not the Marilyn that's in here because she undergoes a great transformation," Barsa contends. "The Marilyn in this movie that was shot in the years '46 or '47 was still under age which was very dangerous back then."

What do you think? Is she the real deal, or simply a Marilyn impersonator who was ahead of her time?