A North Korean envoy has rejected a Malaysian autopsy finding that VX nerve agent killed Kim Jong Nam, saying the man probably died of a heart attack because he suffered from heart disease, diabetes and high blood pressure.
Malaysia dismissed the claim on Thursday.
The death of Kim, the estranged half brother of North Korea's ruler, has unleashed a diplomatic battle between Malaysia and North Korea.
The autopsy is especially sensitive because North Korea had asked Malaysia not to perform one.
Also Thursday, amid growing fallout from the killing, Malaysia announced it is scrapping visa-free entry for North Koreans.
Malaysian officials say two women smeared VX nerve agent - a banned chemical weapon - on Kim's face as he waited at Kuala Lumpur's airport on February 13. Kim died within 20 minutes, authorities say.
The women, who were caught on grainy surveillance video, have been charged with murder. Both say they were duped into thinking they were playing a harmless prank.
Malaysia's autopsy finding that VX nerve agent killed Kim boosted speculation that North Korea orchestrated the attack.
On Thursday, Ri Tong Il, the former North Korean deputy ambassador to the United Nations, told a news conference that it made no sense to say the two women used such a deadly toxin without also killing or sickening themselves and people around them.
Ri said Kim had a history of heart problems and had been hospitalised in the past. He said he understood that Malaysian officials found medication for diabetes, heart problems and high blood pressure in Kim's belongings.
North Korea does not acknowledge that it was Kim Jong Nam who died. Instead, it refers to the victim as Kim Chol, the name on the diplomatic passport he was carrying. Malaysia has confirmed that the victim was Kim Jong Nam.
National police chief Khalid Abu Bakar brushed off Ri's claim of a heart attack.
