Kuala Lumpur - North Korean leader Kim Jong-Un's half-brother was carrying a VX 'antidote' when he was assassinated with the deadly nerve agent in a stunning Cold War-style hit, a lawyer said on Friday.

Kim Jong-Nam had 12 tablets of Atropine in his backpack when he was attacked, said defence lawyer Gooi Soon Seng, citing testimony from the ongoing trial of the two women accused of killing him.

Indonesian Siti Aisyah and Vietnamese Doan Thi Huong, in their 20s, allegedly carried out the hit at the Kuala Lumpur International Airport on February 13 as Kim waited to board a flight to Macau.

Kim died in agony shortly after the VX – so deadly it is classified by the United Nations as a weapon of mass destruction – was wiped on his face.

The pair, who were arrested days after the assassination and face death by hanging if convicted, pleaded not guilty to murdering Kim Jong-Un's estranged half-brother at the start of their trial in October.

The women say they were tricked into believing they were taking part in a prank for a reality TV show, and their lawyers have blamed North Korean agents.

A poison expert from the Malaysian government testified this week that Kim was carrying Atropine, which has several medical uses including treatment for people who have been attacked with nerve agents such as VX.

K. Sharmilah told the Shah Alam High Court that the police sent items from the case for her to test, including a bottle containing 12 white tablets that she concluded were Atropine.

While it can be used against VX, it also has other uses such as treating stomach cramps.

Gooi, who is defending Aisyah, added that the "motive and reason (why Kim was carrying Atropine) was never established".

Kim's murder sparked a furious row between Malaysia and North Korea, which was suspected of ordering the assassination. Pyongyang has denied the allegation.