The legendary star, 81, was hospitalised last week after complications during throat surgery and remained in a coma until Wednesday this week. She suffered a cardiac arrest and died on Thursday, reported TMZ.
The Medical Examiner's Office said they completed the autopsy today and will need more information from further studies, which will include toxicology testing and interviewing medical professionals who took part in her surgery last week.
Rivers suffered cardiac and respiratory arrest while was undergoing a minor elective procedure at the clinic.