Sage Stallone's autopsy has been completed, but his cause of death remains unknown.

The 36-year-old son of actor Sylvester Stallone was found dead at his Los Angeles home on Friday.

The LA Times newspaper reports that authorities are still awaiting toxicology reports, although the autopsy was performed Sunday morning. The coroner's office will receive these test results in around six weeks.

There is speculation Sage suffered an accidental prescription drug overdose. Assistant Chief Coroner Ed Winter confirmed prescription medication bottles were found near Sage's body.

His lawyer and close friend George Braunstein insists that the young man didn't even drink alcohol. George added that Sage was planning to wed his long-term girlfriend in Las Vegas next weekend and had given no indication anything was wrong.

Sources claim that police are still trying to determine whether Sage's cause of death was accidental or intentional.

Sage made his movie debut alongside his father in the 1990 film Rocky 5. He played legendary character Rocky's son Robert Balboa in the feature.

He also appeared in 1996 film Daylight. That same year Sage co-founded Grindhouse Releasing, a company that is dedicated to restoring and preserving exploitation movies, with film editor Bob Murawski.