A book coming out this week and a television report based on it say Marilyn Monroe was killed by the Mafia to expose then-Attorney General Robert Kennedy's romance with the actress, a plot that failed its purpose.

Kennedy was saved from scandal when Los Angeles authorities declared Monroe's death a suicide, according to a book titled "Double Cross," to be published by Warner Books, and a three-part expose beginning Monday on the nationally syndicated TV show, "Hard Copy."The author of the book, Chuck Giancana, appears on the TV series. He is the nephew and godson of Sam Giancana, the late Chicago mob boss, who was one of the Mafia leaders targeted by Kennedy for prosecution or deportation.

Some theorists say President John F. Kennedy was assassinated at the order of the mob, probably the Carlos Marcello organization in New Orleans, in the belief that this would end his brother's term as attorney general and his harassment of organized crime figures.

Giancana writes in his book that his uncle, longtime boyfriend of singer Phyllis McGuire and well-known in entertainment circles, romanced Monroe shortly before her death.

The elder Giancana bugged Monroe's Hollywood apartment to get information on the Kennedy brothers, both of whom have been linked romantically with the super star. Then he ordered her death, Giancana said, hoping to disgrace Robert Kennedy.

According to the author, the attorney general had a rendezvous with Monroe at her Hollywood apartment on the evening of Aug. 4, 1962, and after he left, a team of four Mafia hitmen visited her and "forced her nude body to the bed."

"Calmly, and with all the efficiency of a team of surgeons, they taped her mouth shut" and inserted a rectal suppository filled with Nembutal, a sleep-inducing barbiturate powerful enough to induce death, Giancana wrote.

Monroe's nude body was found on her bed early the next day, and experts ruled it was a "probably suicide" after finding a high level of barbiturates in her bloodstream. There was an empty vial of Nembutal on a bedstand, according to police reports.

Monroe's psychoanalyst told police she had tried to kill herself twice before.

Giancana said his uncle had expected "hordes" of police to search the apartment and find evidence that "Bobby Kennedy had been there just hours earlier." But the FBI removed all traces that would have incriminated Kennedy, he said.