BANGKOK - PORNTHIP Rojanasunand, director of Thailand's Central Institute of Forensic Science, said Carradine may have died attempting a sex act known as auto-erotic asphyxiation - cutting off oxygen to the brain for sexual arousal.

The body of American actor David Carradine, best known for the 1970s TV series 'Kung Fu,' was found in a hotel room closet with a rope tied to his neck and genitals, and his death may have been caused by accidental suffocation, Thai police said on Friday.

The practice is said to result in a form of giddiness and euphoria - similar to alcohol or drug intoxication - that enhances the sexual experience.

'If you hang yourself by the neck, you don't need so much pressure to kill yourself. Those who get highly sexually aroused tend to forget this fact,' Mr Pornthip said.

The 72-year-old actor's body was discovered on Thursday in his luxury suite at Bangkok's Swissotel Nai Lert Park Hotel. Police initially said they suspected suicide, though Carradine's associates had questioned that theory and authorities later said no suicide note was found in his room.

Police Lt Gen Worapong Chewprecha told reporters that Carradine was found with a rope tied around his genitals and another rope around his neck.

'The two ropes were tied together,' he said. 'It is unclear whether he committed suicide or not or he died of suffocation or heart failure.'

Thai police completed an autopsy on Carradine on Friday. But Police Col Somprasong Yenthuam, superintendent of the Lumpini police station, which is handling the case, said results would not be ready for at least three weeks because the cause of death was unclear.

Dr Nanthana Sirisap, director of Chulalongkorn Hospital's Autopsy Center, told reporters that the autopsy was conducted because of the 'unusual circumstances surrounding Carradine's death,' but did not elaborate.

The body was later removed from the hospital to an undisclosed location by US Embassy representatives while preparations were being made for its repatriation to the United States. -- AP