Kim Jong-Nam, the half-brother of North Korea’s leader, Kim Jong-Un, was killed using the highly toxic liquid nerve agent called VX, Malaysian police have said.
VX – also known as O-ethyl S-diisopropylaminomethyl methylphosphonothiolate – is classified by the United Nations as a weapon of mass destruction.
Malaysian Inspector General of Police, Khalid Abu-Bakar, said that one of the two women suspected of involvement in the poisoning was also suffering the effects of VX, which is only used in chemical warfare.
The discovery follows a preliminary analysis of swabs taken from the face and eyes of Kim Jong-Nam, but more items linked to the attack at Kuala Lumpur airport were still being analysed.
Kim Jong-nam died on 13 February from a seizure while being taken to hospital after complaining that a woman had sprayed chemicals in his face at Kuala Lumpur airport.
The police had earlier said that two attackers rubbed a liquid on him before walking away and quickly washing their hands. CCTV images also showed this.
Asked about the possibility that North Korean agents might have imported the world’s most toxic nerve agent and deployed it in an international airport, a source close to the Malaysia government said: “Not very diplomatic.”
South Korea said the use of VX was a “blatant violation” of international norms.
“We are shocked by the latest revelation by the Malaysian authorities that VX … was used in the death of Kim Jong-Nam,” Seoul’s foreign ministry said in a statement.
“The use of any chemical weapons is strictly banned for any reason and in any place,” it added.
The Malaysian Police IG said that authorities were determining how VX entered the country, adding that the terminal where Kim Jong-Nam was killed, in a budget airline departure lounge, would be decontaminated.
As a weapon, VX does not quickly dissipate and can remain on material or the ground for long periods.
An employee at Malaysia Airports Holdings, the company that manages the airport, told the Guardian it had not closed the terminal or been contacted by police about a decontamination since the attack 11 days ago.
China, which afforded a level of protection to Kim Jong-nam during his stay there and in Macau, issued a cautious response to the revelations.
The foreign ministry spokesman Geng Shuang told reporters that Beijing was aware of media reports about the use of chemicals classified by the UN as a weapon of mass destruction.
“We have also noted the relevant remarks made by Malaysia and the latest developments,” Geng said.
“So far we have seen only preliminary information. There has been no conclusion with regards to this incident.”
Liang Yabin, a research fellow at the institute of international strategic studies at the Communist party’s Central Party School, said that, if confirmed, the use of such chemical weapons at an international airport would represent a violation of Malaysian sovereignty and be “simply intolerable”.
The US government’s Centers for Disease Control and Prevention describes VX as the most potent of all nerve agents and one that would be lethal on contact with the skin unless immediately washed off.
The agency says exposure to a large dose of VX may result in convulsions, loss of consciousness, paralysis and fatal respiratory failure. Kim Jong-nam is reported to have complained of pain in his face shortly after the attack. A leaked photo at the medical centre shows him laid back on a chair with his eyes closed.
Saddam Hussein was accused of using VX during the Iran-Iraq war and there are concerns that stockpiles exist in Syria. Only the US and Russia have said they possess VX or a similar agent.
North Korea is thought to have one of the world’s largest stockpiles of chemical weapons, and is one of six countries not to have signed or acceded to the Chemical Weapons Convention, CWC), according to the US non-profit organisation the Nuclear Threat Initiative.