Kim died within 20 minutes of attack

Kim Jong-Nam was dead within 20 minutes of being attacked and would have suffered a "very painful death" as his major organs shut down, Malaysia's health minister said yesterday.

The estranged half-brother of the North Korean leader was killed with lethal nerve agent VX, police have revealed, after he was ambushed at Kuala Lumpur airport on February 13.

Two women can be seen shoving something into Kim's face in leaked CCTV footage of the brazen assassination before he seeks help.

"He died in the ambulance. He fainted in the clinic," Health Minister S. Subramaniam told reporters.

"From the time of the onset (of the attack) he died within 15 to 20 minutes."

Autopsy results suggested the 45-year-old died from "very serious paralysis" due to a lethal nerve agent, Subramaniam said earlier yesterday.

Police are holding two women suspected of staging the attack as well as a North Korean man.

VX is so deadly it is listed by the UN as a weapon of mass destruction and overnight the scene of the killing in the budget terminal of Kuala Lumpur International Airport was swept by civil defence personnel in hazmat suits before being declared safe.

Both women suspected of carrying out the attack insisted they thought they were taking part in a prank video, although Malaysian police have said they knew what they were doing.