Marilyn Monroe Sex Film

A 15-minute film of Marilyn Monroe engaging in an oral sex act with an unidentified man will be kept from public view by a New York businessman who has bought it for $1.5m (£750,000), the broker of the deal said today.

Memorabilia collector Keya Morgan said he recently arranged the sale of the silent, black-and-white film from the son of a dead FBI informant who possessed it to a wealthy Manhattan businessman who wants to protect Monroe's privacy.

"The gentleman who bought it said out respect for Marilyn he's not going to make a joke of it and put it on the internet and try to exploit her," said Morgan.

"That's not his intention and I would never get my name involved if that were to happen."

Monroe is clothed and the man's head remains out of the frame for the entire 15 minutes of the film, said Morgan, who viewed the footage.

Monroe was rumoured to have had an affair with former US President John F Kennedy, and Morgan said former FBI director J Edgar Hoover, a Kennedy rival, went to great lengths to try to prove it was Kennedy in the film.

One of Monroe's ex-husbands, the late baseball great Joe DiMaggio, once tried to buy it from the collector for $25,000 (£12,500) but "he would not part with it", according to declassified FBI files provided by Morgan.

Morgan is a well-known collector who owns memorabilia from the estates of Monroe and DiMaggio and said he was friends with Monroe's other two husbands, Jim Dougherty and Arthur Miller.

He said he learned of the existence of the film while working on a documentary about Monroe, who died in August 1962 at age 36. A former FBI agent told him about it, and Morgan said he confirmed it by tracking down the son of the FBI informant, who had provided a copy to the FBI.

The late informant's son had the original while the copy remains classified in the FBI files, said Morgan, whose deal was first reported by the New York Post today.

"The FBI agent that I interviewed said J Edgar Hoover was completely obsessed. A team of nine individuals were analysing the tape inside a lab. J Edgar Hoover brought in a few prostitutes who allegedly had been with President Kennedy and they tried to ... see if that was really President Kennedy."

FBI spokesmen in New York and Washington did not immediately return phone calls seeking commen