The estranged half-brother of North Korean dictator Kim Jong Un died within 20 minutes of being exposed to nerve agent VX, Malaysia's health minister said on Sunday.

Kim Jong Nam (pictured) died on February 13 at Kuala Lumpur's airport after two women wiped a liquid on his face in what Malaysian police have described as an assassination.  Police announced Friday that the Vietnamese and Indonesian women used the banned agent.

Health Minister Subramaniam Sathasivam said 10 milligrams of the nerve agent is lethal and that he suspected a higher dose was used.

"The doses were so high and it did it so fast and all over the body, so it would have affected his heart, it would have affected his lungs, it would have affected everything," Subramaniam told reporters.

"He died in the ambulance ... I would think it was about from the time of application 15 to 20 minutes," he said when asked how long it took for Kim to die.

'Prank show'

On Saturday, Indonesian and Vietnamese diplomats met with the two arrested women, who both said they thought they were part of a prank show. Siti Aisyah, the Indonesian, said she was paid $90 (85 euros), embassy officials said.

Abdul Samah Mat, the police official leading the investigation, said Aisyah vomited in the taxi after fleeing the airport but appeared to be fine now. Both women are being tested to see if they received an antidote so the nerve agent wouldn't kill them.

Malaysia hasn't officially accused the North Korean government of carrying out the attack, but the attack has already strained relations. Experts say only a sophisticated state actor could produce VX. North Korea is not a signatory to a treaty banning the agent and has a chemical weapons program.

Exiled brother

Police believe four North Korean suspects who fled the country the same day of the attack gave the nerve agent to the women. They also want to speak to a North Korean diplomat who has diplomatic immunity. In addition to the two women, police are holding a North Korean man.

Abdul Samah also said a condominium rented by the four North Korean suspects was raided by police last week and tests for chemical traces were still ongoing.

Early Sunday, police wearing protective gear searched for traces of the nerve agent at the airport but found no traces. The area was not cordoned off and thousands of people have passed through the airport since the incident, raising concern they could have been exposed.

Subramaniam said that so far there have been no reports of anyone being sickened by VX, but that the medical crew that attended to Kim are under supervision.

Kim had lived in exile for years and posed no apparent threat to his half-brother, who has been known to execute even some of his closest aides. South Korea has blamed North Korea for the killing, saying the regime in Pyongyang carried out a "blatant violation of the Chemical Weapons Convention and other international norms."