The autopsy began at 11 a.m. EDT, though results were not likely to be final until toxicology tests could be completed.
The process could take up to six to eight weeks, Ed Winter, L.A. County Assistant Chief Coroner told reporters Friday morning.
However, if a cause can be determined by the autopsy, they will announce the results, said Los Angeles County Coroner Investigator Jerry McKibben.
There has been speculation that drugs may have played a role in the death of the icon, with TMZ citing sources who claim he was given a "heavy dose of morphine" before his death. Other reports claim that Jackson received a shot of Demerol — a similar narcotic— shortly before his death.
Brian Oxman, a former attorney of Jackson's and a family friend, said he was concerned about Jackson's use of painkillers and he warned the singer's family about possible abuse.