KUALA LUMPUR, Malaysia (AP) — No cause of death has been determined yet for the exiled member of North Korea's ruling family who died last week after apparently being poisoned in a Kuala Lumpur airport, officials said Tuesday.

The autopsy showed no evidence of a heart attack in Kim Jong Nam's death, or sign of puncture wounds, Director General of Health Noor Hisham Abdullah told reporters.

Asked if there was any indication that he had been poisoned, Noor Hisham said medical specimens from the autopsy had been forwarded to experts to determine the cause of death. "We have to confirm with the lab report before we can make any conclusive remark," he said.

No family members have come forward to claim the body. Kim, the older half brother of North Korea's ruler, had spent most of the past 15 years living in China and Southeast Asia. He is believed to have had at least three children with two women.

The attack spiraled into diplomatic fury when Malaysia refused to hand over Kim's corpse to North Korean diplomats after his death, and proceeded with an autopsy over the diplomats' objections. The two nations have made a series of increasingly angry statements since then, with Malaysia insisting it is simply following its legal protocols, and North Korea accusing Malaysia of working in collusion with its enemy, South Korea.

South Korea's spy agency believes North Korea was behind the killing, but has produced no evidence to back that up.

Isolated North Korea has a long history of ordering killings of people it views as threats to its regime. While Kim Jong Nam was not known to be seeking political power — he was best known for his penchants for drinking, gambling and expensive restaurants — his position as eldest son in the ruling family could have made him appear to be a danger.

Police have so far arrested four people carrying identity documents from North Korea, Malaysia, Indonesia and Vietnam. Those arrested include two women who were allegedly seen approaching Kim on Feb. 13 as he stood at a ticketing kiosk at the budget terminal of the Kuala Lumpur airport.

Grainy video from a series of airport security cameras obtained by Japan's Fuji TV seems to show the two women approaching Kim from different directions that morning, with one slipping up behind him and appearing to hold something over his mouth for a few seconds. Then the women turn and calmly walk off in different directions. Kim, a heavyset man in his mid-40s, walked to the airport clinic, but died soon after en route to a hospital after suffering a seizure, officials say. He was at the airport to fly to Macau, where he had a home.

At least one of the women has said she was tricked into taking part in the attack, believing it was part of a comedy TV show stunt.

Investigators are still looking for four North Korean men who arrived in Malaysia on different days beginning Jan. 31 and flew out the day of the attack.