While Monjack reportedly suffered heart problems and his body was found with some prescription drugs in his system, Los Angeles Assistant Chief Coroner Ed Winter said he did not believe drugs or heart disease were contributing factors in his death, E! News reported.
Monjack, a British screenwriter, died May 23 in the Hollywood home he once shared with Murphy.
Murphy died in the same home Dec. 20, with the Los Angeles Coroner listing acute pneumonia as the primary cause of the "Clueless" starlet’s death (severe anemia and drug intoxication were named contributing factors).
The pair were reportedly buried next to each other at Forest Lawn Memorial Park in Los Angeles.
Monjack’s official autopsy report will be withheld for two weeks, as the coroner’s office will conduct one more examination at the request of his family, E! reported.