Sage Stallone is seen during "Rocky Balboa" World Premiere - Arrivals at Grauman's Chinese Theatre in Hollywood, California, United States. (Albert L. Ortega/WireImage/Getty Images)
By Leezel Tanglao, ABC News
There were no signs of foul play in connection with the death of Sage Stallone, the 36-year-old son of Sylvester Stallone, authorities said.
Sage Stallone was found dead in his Los Angeles apartment by authorities and a housekeeper Friday after worried loved ones sensed trouble.
His cause of death remains undetermined. Los Angeles County Assistant Coroner Ed Winter told The Associated Press that an autopsy will be conducted in the next several days.
"There had been no personal contact with the deceased in the last few days," said Sgt. Jim Parker with the Los Angeles Police Department.
Authorities said there were no signs of forced entry and no suicide note. But there were prescription drugs found.
"There are some prescription bottles, however I'm not going to detail what they are or how many," Winter said.
Sylvester Stallone's publicist Michelle Bega told the AP that the actor is "devastated and grief-stricken over the sudden loss of his son."
"His compassion and thoughts are with Sage's mother, Sasha," Bega said in a statement.
"Sly adored his son, he really adored his son. He was his biggest supporter in terms of his acting, in terms of his directing. And Sage was reportedly at a very good time in his life," said Howard Bragman, ABC News consultant.
Sage Stallone's longtime attorney George Braunstein said his client didn't seem depressed and said "everything was up and positive."
Sage Stallone played Rocky Balboa's son in "Rocky 5" in 1990 and appeared in the film "Daylight" with his father. He also directed the 2006 short film "Vic."
"He was beautiful. He was physically beautiful ... emotionally beautiful," said Carol Lynley, who starred in "Vic."
ABC News Radio and The Associated Press contributed to this report.