A highly-toxic agent was used in the assassination of Kim Jong-nam, the estranged half-brother of North Korean leader Kim Jong-un, the Malaysian police said on Friday.
Kim died last week after a suspected poisoning while on his way to catch a flight to Macau from the Kuala Lumpur Airport.
Police chief Khalid Abu Bakar said in a statement that the chemical was identified as the VX nerve agent and was found on swabs taken from Kim's eyes and face, The Star newspaper reported.
The nerve agent used to kill Kim is considered an extremely toxic substance and is classified as a weapon of mass destruction by the UN. Bakar said that one of the two women who staged the attack became unwell as a result of poisoning from the same chemical.
The authorities said they intend to decontaminate the Kuala Lumpur Airport and areas the suspects were known to have visited, according to the report.
Bakar said other exhibits were still under analysis and that the police were investigating how the banned substance might have entered Malaysia.
"If the amount of the chemical brought in was small, it would be difficult for us to detect," he said.
According to the police chief, a Vietnamese woman and an Indonesian woman wiped a liquid on Kim's face and later washed their hands and fled the scene.
His body remains in the hospital's mortuary, amid a diplomatic dispute over who should claim it.
Malaysia said it was clearly an attack by North Korean agents. Four people are in custody, including one North Korean and the two women Kim interacted with at the airport, according to reports.
Malaysia's Deputy Prime Minister Ahmad Zahid Hamidi said that according to embassy documents the body was of North Korean leader Kim Jong-un's half-brother, but North Korea's ambassador to Malaysia denied the dead man's identity.
Pyongyang said that Malaysia was responsible for the death of one of its citizens. It also accused Malaysia of trying to politicise the return of his body, saying its insistence on securing DNA samples from Kim's family before handing the body over was "absurd".