Malaysian police said preliminary toxicology tests identified VX nerve agent on the eyes and face of Kim Jong-nam, the estranged half brother of North Korean leader Kim Jong-un, following his killing at Kuala Lumpur’s airport on February 13. Two women allegedly wiped chemicals across his face while he waited for a flight to Macau, where he lived with his family. He sought medical assistance, suffered convulsions and died while being transported to hospital. He had been travelling under the name Kim Chol.

VX is an exceptionally potent chemical warfare agent banned under the 1993 Chemical Weapons Convention and classified by the United Nations as a weapon of mass destruction. It disrupts nerve function and can be fatal in minute quantities. Its oily consistency and slow evaporation raised concerns about contamination at the airport, in the ambulance and at medical facilities. The airport had remained open for more than ten days without decontamination; police subsequently said cleanup was beginning or being arranged. No passengers, airport employees or medical staff were reported ill.

The two suspected attackers are Vietnamese and Indonesian women. Police said one experienced vomiting after the incident, without identifying her. Investigators argued that the women’s immediate handwashing indicated awareness that they had handled poison. Relatives and acquaintances disputed their knowing involvement, suggesting they had been deceived. Toxicologists questioned how they survived handling such a dangerous substance and raised possible antidote use as an explanation, although this remained speculation. Authorities were also investigating how VX entered Malaysia.

Malaysia linked the killing to North Korean agents and sought several North Koreans, including an embassy diplomat and an employee of the state airline Air Koryo. The passages give differing custody totals of three or four people. North Korea fiercely denied responsibility, accused Malaysia of fabricating evidence in cooperation with its enemies and challenged the post-mortem examination. It continued to describe the victim only as a North Korean citizen, declining to acknowledge him as Kim Jong-nam. A North Korean statement blamed Malaysia because the death occurred there and invoked the country’s status as a nuclear weapons state. Malaysia’s foreign minister warned that North Korea’s ambassador could be expelled over his accusations.

Kim Jong-nam, the eldest son of former leader Kim Jong-il, had once been considered a possible successor. His prospects reportedly faded after he was caught entering Japan on a false passport in 2001. He later lived abroad and publicly criticized North Korea’s policies and hereditary succession.

The discovery of VX intensified scrutiny of North Korea’s suspected chemical weapons program. The country has not signed the Chemical Weapons Convention, and outside estimates place its chemical weapons holdings at roughly 2,500–5,000 tons, with annual production capacity potentially rising sharply during a crisis. Its suspected arsenal includes mustard, phosgene, sarin and V-type agents. The reports also recalled Aum Shinrikyo’s VX attacks in Japan in 1994–95. The investigation has severely strained previously accommodating relations between Malaysia and North Korea, while responsibility, the suspects’ knowledge and the precise method of exposure remain unresolved.