Los Angeles: Actor Sylvester Stallone has hired a private investigator to find out how his 36-year-old son, Sage, died.

He was found unresponsive on Friday at his Studio City apartment.

Sylvester wants P.I. Scott Ross, Los Angeles County Coroner’s office, to figure out what happened to Sage, and even though there is no evidence of foul play, he is not ruling that out.

He also wants to know about Sage’s final weeks, whether he was using drugs or consuming alcohol, and if there was anything troubling his son.

An initial autopsy on his body, which was completed on Sunday, proved inconclusive and the cause of death is not expected to be known for up to two months until the toxicology tests are completed.

Sage Stallone’s Death Investigation