Los Angeles/Bangkok - The body of US actor David Carradine was due to be flown back to the United States on Saturday, as his family has asked the FBI to conduct an investigation to clarify his mysterious death last Thursday in a five-star hotel in Bangkok.

In an interview Friday with TV-presenter Larry King on CNN, Mark Geragos, lawyer of Carradine's brother said that the family does not believe that the actor committed suicide.

According to Geragos, Carradine's family has ordered the FBI to start an investigation after receiving contradictory reports from Bangkok's police on the posssible causes of the former Kung-Fu star.

At first Thai police said it was suicide, but after an autopsy of the body was conducted, forensic experts at Chulalongkorn Hospital concluded he had died of suffocation.

Well-known Thai forensics expert Porntip Rojanasunan said the actor might have died from "auto-erotic asphyxiation," according to the Bangkok Post newspaper.

"I don't know if you want to call it accidental," Chuck Binder, Carradine's manager, told CNN. He disputed suicide because the actor's career was on a roll and his life was on a resurgence.

Binder added that he had spoken on the phone with a producer of the movie "Stretch" who was working in Thailand with Carradine to inform him on the latest developments.

"I do not want to get in the middle of the investigation, but this guy said to me for sure there was foul play," Binder said.

Tiffany Smith, co-manager of the 72-year-old actor told CNN that once the body has arrived to the United States an autopsy will be conducted to find out the exact cause of death. However this can take up to four weeks.

The body of Carradine, 72, who first shot to fame in the 1970s Kung Fu television series, was found Thursday morning in the closet of his suite by maid at the five-star Swissotel Park Nai Lert Bangkok in what forensic experts described as an "abnormal" death scene.

The Bangkok Metropolitan Police commissioner, Lieutenant General Worapong Chewpreecha, confirmed that Carradine had been found with his neck bound to his penis by a shoestring and his hands tied.

DNA samples taken from Carradine's body would be used to determine if there was anyone else in his room at the time of his death, the hospital said in a press statement.

Carradine recently starred in Quentin Tarantino's two-part movie Kill Bill. His first major role was as the fugitive half-Chinese Shaolin monk Kwai Chang Caine in the TV drama series Kung Fu. (dpa)