A new true-crime account of Marilyn Monroe's final day offers disturbing allegations of a confrontation with Robert F. Kennedy as he searched for the actress's rumored diary of political secrets.

Per RadarOnline, the allegations emerge in bestselling author James Patterson's explosive, brand-new book "The Last Days of Marilyn Monroe," which revisits longtime controversies surrounding the Hollywood icon's 1962 death.

The book begins with reports of federal interest in Monroe shortly before her death. Patterson writes that then-FBI Director J. Edgar Hoover received a report naming Monroe as a "security matter" and potential "Communist."

The book continues as Patterson then describes RFK ending contact with Monroe after their affair. Patterson writes that Monroe grew furious, accusing RFK of giving her "the sudden cold shoulder – so reminiscent of what happened recently with Jack."

One finds the reported warning from Monroe to the director, Bob Slatzer: "I might just hold a press conference. I've certainly got a lot to say! Patterson sets up the quote neutrally.

Patterson also cites investigator Fred Otash, who reportedly planted a microphone on Monroe's phone at her request. After setting the recording scene, Patterson relates Otash's notes, writing that the tapes captured RFK and actor Peter Lawford in a heated argument with Monroe.

Introducing the next claim neutrally, Patterson writes that Monroe accused the Kennedy brothers of mistreating her, saying she "was passed around like a piece of meat."

The confrontation allegedly escalated over RFK demanding the whereabouts of Monroe's diary. Patterson summarizes the scene before quoting the attorney general: "Where is it? Where the f--- is it? We have to know. It's important to the family.'"

According to the book, Monroe screamed as RFK searched her home. Patterson says RFK tried to muffle her cries, writing that "Bobby gets the pillow, and he muffles her on the bed to keep the neighbors from hearing."

The book says hours later, Monroe attempted to calm herself with pills and made a series of calls. Patterson describes her mental state before quoting her call with Sydney Guilaroff: "'Danger... betrayals... men in high places... clandestine love affairs,'" followed by, "'I know a lot of secrets about the Kennedys. Dangerous ones.'"

Monroe was found dead on August 4, 1962. The cause of death was determined as acute barbiturate poisoning.

In other news, newly declassified FBI files have revived speculation about Marilyn Monroe's alleged pregnancy with John F. Kennedy during his 1960 campaign, according to People. Sources claimed Monroe became pregnant while filming Let's Make Love and told JFK, who allegedly insisted she could not have the baby due to potential political scandal.

Insiders also alleged Monroe later had an abortion while hospitalized for "exhaustion," believed Kennedy would eventually leave his wife, and continued seeing him before becoming involved with Robert F. Kennedy.

The documents have fueled longstanding conspiracy theories about Monroe's death, and her reported plans to reveal secrets about the Kennedys and the alleged pregnancy.