A secret sex tape of Marilyn Monroe recently sold for $1.5 million, according to a report in the New York Post.

A copy of the 15 minute, 16 mm film was purchased by a New York businessman who plans to lock it up, memorabilia collector Keya Morgan told the paper. The original film is reportedly held by the FBI and still remains classified.

The flick, reportedly shot in the 1950s, shows the blonde bombshell engaging in oral sex with an unidentified male. Former FBI Director J. Edgar Hoover reportedly had his agents spend weeks trying to ascertain whether the man was either John F. Kennedy or Robert F. Kennedy, the paper said.

The black-and-white film shows the actress on her knees in front of the man, Morgan told the paper. The collector said he found the film while doing research for a Monroe documentary.

Heavily redacted, declassified FBI documents from the 1960s talk about a "French-type" film starring the late actress, who died in 1962 from an overdose of prescription drugs.

Click here to read the full story at the New York Post.

For more news, entertainment and sports coverage, click here for NYPost.com.