Sage Stallone's attorney has insisted he never drank alcohol or took drugs.

The 36-year-old son of actor Sylvester Stallone was found dead at his Hollywood Hills home on Friday. There is speculation he suffered an accidental prescription drug overdose, but his lawyer and close friend George Braunstein thinks that is untrue.

"Never, no, not from the day I met him," he said, when asked if he'd seen Sage take drugs or drink alcohol. "I never knew him to drink alcohol. I never saw him take drugs. I never knew of anything like that at all.

"I'm going to wait to see what the coroner says. I think it was either natural causes or a terrible accident. I don't think it had anything to do with drugs, he wasn't that kind of guy. He wasn't anyone trying to take his life."

Assistant Chief Coroner Ed Winter confirmed prescription medication bottles were found near Sage's body.

George insists the actor-and-director's only vice was enjoying sweet treats.

"Sage didn't even drink. There was a report that his room was filled with liquor bottles. Actually, they were empty bottles of Dr. Brown's Cream Soda," he told People.

He added to E! News: "His mother Sasha Czack is devastated. They're trying to sort everything out and plan a funeral. Sylvester called, he's upset too. They may be celebs, but they're regular parents. It's tragic."

George added Sage was planning to wed his long-term girlfriend in Las Vegas next weekend and had given no indication anything was wrong.

Arnold Schwarzenegger has shot several films with Sylvester recently and has released a statement about Sage's death.

"My thoughts and prayers are with Sly and his family. Sly has become a great friend over the past couple decades, and I know how important his children are to him. I want him to know that my family and I, and his fans all over the world, support him during this difficult time," it read.