Carradine's manager Thursday confirmed the 72-year-old "Kung Fu" and "Kill Bill" star was found dead in a hotel in Bangkok. The film and TV star had been in the Thai city filming a movie.
Officials initially said they suspected Carradine, who was discovered hanging in a closet, committed suicide.
Police later offered another possible explanation for his death, while a spokesman for the Carradines said the family is "100 percent" certain he did not intentionally kill himself.
"There was a rope tied around his neck and another rope tied at his sex organ, and the two ropes were tied together and hung in the closet," The Daily Telegraph Friday quoted Thai police commander, Lieut. Gen. Worapong Siewpreecha, as saying. "Under these circumstances we cannot be sure that he committed suicide, but he may have died from masturbation."
However, TMZ reported Friday Carradine's family thinks foul play may have been involved in his death.
Carradine's manager, Chuck Binder, told the entertainment news Web site the actor was found with his hands tied behind his back.
An autopsy reportedly was conducted on the actor's body Friday, but the results not immediately made available. TMZ said his body has been shipped back to the United States.