The dose of nerve agent given to North Korean ruler Kim Jong-un's half-brother was so high that it killed him within 20 minutes and caused "very serious paralysis", Malaysia's health minister has said.
Kim Jong-nam died on February 13 at Kuala Lumpur's airport in what Malaysian police say was a well-planned hit by two women who wiped a liquid on his face.
Police revealed on Friday that the banned chemical weapon VX nerve agent was used to kill Mr Kim, raising the stakes in the case.
Health Minister Subramaniam Sathasivam said the dose was so high that he showed symptoms within minutes.
Mr Kim fainted at the airport clinic and died in an ambulance en route to hospital, he said.
"VX only requires 10 milligrams to be absorbed into the system to be lethal, so I presume that the amount of dose that went in is more than that," he said.
"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."
Asked how long it took Mr Kim to die after he was attacked, Mr Subramaniam said: "I would think it was about, from the time of onset, from the time of application, 15 to 20 minutes."
Malaysia has not directly accused the North Korean government of being behind the attack, but officials have said four North Korean men provided two women with poison to carry it out.
The four men fled Malaysia on the same day as the killing, while the women - one from Indonesia and the other Vietnamese - were arrested.
Experts say the nerve agent used to kill Mr Kim was almost certainly produced in a sophisticated state weapons laboratory and is banned under an international treaty.
But North Korea has never signed the treaty and spent decades developing a complex chemical weapons programme.