LATEST: Marilyn Monroe's biographer has slammed a newly-released FBI report which claims the star was the victim of a murder conspiracy. Monroe, 36, was found lying naked, faced down on her bed at her Brentwood, California home on 5 August 1962. A coroner ruled the cause of death as 'probable suicide' by barbiturate poisoning, but many conspiracy theorists believe her rumoured affair with Kennedy had something to do with her unexpected death. However, her biographer ANTHONY SUMMERS refuses to believe the newly-released FBI document, unearthed by Australian filmmaker PHILLIPE MORA. It claims Monroe was tricked into killing herself by associates, including former US attorney general ROBERT KENNEDY, who promised the actress would be rescued in time. Summers, who claims to have had access to the FBI documents over 20 years ago, rubbishes the allegations of foul play as unfounded. He says, "I had this document in 1984 when it was first released by the FBI. I had the uncensored version of it the same year. "I got it from a private source in California who in turn had been in touch with a man called FRANK CAPELL, who was a right-wing agitant, keen to lay blame for Monroe's death at the feet of the Kennedys. "I didn't use it because I believed it was full of misguided gibberish and rumour. It's a shame because there are some real mysteries surrounding Monroe's death - but I don't think murder is one of them."