The official cause of death was given as "drowning and effects of atherosclerotic heart disease and cocaine use". The coroner's office said the death was an "accident".
The 48-year-old pop star was found submerged in a bath at the Beverly Hilton on Febuary 12, the night before the Grammy Awards.
The release of autopsy findings ends weeks of speculation about what killed her.
No trauma or foul play were suspected in the entertainer's death, Mr Harvey said.