Sylvester Stallone's son died from a heart attack and had no illegal drugs in his system, according to the Los Angeles coroner's office.

Sage Stallone, 36, was found dead on July 13 at his home in Los Angeles.

Coroner's Lieutenant Fred Corral said: "The cause was atherosclerotic coronary artery disease. A natural death. The toxicology tests were negative for drugs."

The Stallone family said they were "glad to hear it was all completed" after they were notified of the findings.

At the time of his son's death, Stallone said: "When a parent loses a child there is no greater pain."

"Therefore I am imploring people to respect my talented son's memory and feel compassion for his loving mother Sasha."

Sage was the Rocky actor's oldest child by first wife Sasha Czack.

Stallone, 66, added: "Sage was our first child and the centre of our universe and I am humbly begging for all to have my son's memory and soul left in peace."

Stallone was found dead in his home by an employee and a relative on July 13. No foul play had been suspected, and toxicology results showed only a minimal amount of the pain-relieving drug hydrocodone in his system.

Sage Moonblood Stallone was the oldest of Rocky star Sylvester Stallone's children and co-starred with his father in two films.

In the 1990 film Rocky V, Sage played Rocky Balboa Jr at the age of 14 and also appeared alongside his father in the 1996 film Daylight.

Source: Press Release