The book 'Murder of Marilyn Monroe: Case Closed' by Jay Margolis and Richard Buskin has claimed that the actress did not committed suicide, in fact she was a murdered.

The authors of the book allege that Robert Kennedy, Ralph Greenson and Peter Lawford pre-planned 36-year-old actress' murder in order to shut her up, the Daily Express reported.

The book also asserts that the 'Some Like It Hot' star had been having a secret affair with JFK, and then his brother Bobby, while also bedding Dr Greenson, and had threatened to expose them.

However, Monroe was also suffering through depression as she struggled with the failure of three marriages, and she also feared being typecast as a 'sex kitten' in Hollywood.

Margolis said that Monroe's death will be argued even over 100 years after the incidence but the reality is that the case is closed and many people refuse to believe that it was murder or suicide but consider it as an accidental overdose.

Nevertheless, complete description of the incident has been provided in the book.