He also called for an end to "speculation and questionable reporting" about the 36-year-old's death, as it emerged that the young actor was actively planning his own wedding, in Las Vegas.

"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," he told celebrity news website TMZ.

"This agonizing loss will be felt for the rest of our lives," he said, adding, "Sage was our first child and the center of our universe and I am humbly begging for all to have my son's memory in full left in peace."

Sage Moonblood Stallone was found dead at his Hollywood home on Friday. An autopsy was carried out on Sunday, but the LA County Coroner's Office said toxicology reports would take some 10 weeks.

Some prescription pill bottles were taken from the apartment, but authorities have said little about the cause of the death. There was no sign of foul play or trauma, or a suicide note, said Ed Winter of the coroner's office.

His father was in San Diego at the annual Comic Con festival to promote his latest movie "Expendables 2" when he was told about his son's death.

Sage Stallone's attorney George Braunstein said he had never seen Stallone take drugs or drink alcohol.

"Never, no, not from the day I met him," Braunstein said. "I never knew him to drink alcohol. I never saw him take drugs. I never knew of anything like that at all," he told E! News.

"The last conversation I had with him, he was telling me about, he was getting married, and he was planning a kind of an exciting costume wedding in Las Vegas," he said.

The young actor appeared in the 1990 film "Rocky V" as Rocky Balboa Jr, the son of his father's title character. The pair also appeared together in the 1996 movie "Daylight."

He is credited with 13 big-screen roles as an actor, while he was a producer on three films, including the 2006 short "Vic," which he also wrote and directed.

Braunstein said the family was "devastated" and is waiting to hear the cause of death, as the funeral is planned.

"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 said.

"He wasn't anyone trying to take his life," he added.

Sapa-AFP

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