Forensic pathologist Dr. Michael Baden said the 72-year-old actor died from an inability to breathe and the way his body was bound helped to rule out suicide.
"The cause of death was asphyxiation, an inability to breathe, now why that happened is still what we're working on," Baden told Reuters.
Carradine was found hanging from the closet with ropes tied around his neck, wrists and genitals and it was speculated the actor may have died from accidental auto-erotic asphyxiation -- which Baden didn't rule out -- but Carradine's family has adamantly denied the claim.
"He didn't die of natural causes, and he didn't die of suicidal cause from the nature of the ligatures around the body, so that leaves some kind of accidental death," Baden said.
Carradine's family hired the famed forensic pathologist to do a follow-up on Carradine's June 4 death. The first autopsy was conducted by officials in Thailand who said it would take a month before the results were available.
Baden said the full determination of Carradine's death wouldn't be available for a week but had earlier ruled out suicide.
Carradine's family indicated the kung fu guru may have been involved in the shady martial arts underground -- an interest that may have led to his death.
"What that means is connected to martial arts and his interest in martial arts," Geragos said on CNN's "Larry King Live" in June. "And there is a suspicion that if there was some foul play, that that may be the first area where they should look."