MIC treasurer-general S Vell Paari has urged for the diplomatic immunity of a North Korean diplomat to be revoked.

"I would urge the inspector-general of police (IGP) Khalid Abu Bakar and attorney-general Mohamed Apandi Ali to look into existing laws for us to revoke the diplomatic immunity of (the diplomat)," Vell Paari said in a statement today.

Previously, Khalid had said that a North Korean diplomat was wanted for questioning with regard to investigations into the death of Kim Jong-nam, the estranged half-brother of North Korean leader Kim Jong-un.

However, he added that the diplomat is immune from arrest by local police, and that Malaysia will adhere to all procedures and protocols involved, to question the man.

Vell Paari said, following the revelation that a chemical weapon substance known as "VX nerve agent" was used in Jong-nam's murder, this proved that his death was not an accident.

Earlier today, Khalid revealed that preliminary reports showed VX nerve agent was used on Jong-nam.

VX is tasteless and odourless and is outlawed under the Chemical Weapons Convention, except for "research, medical or pharmaceutical purposes".

It can be manufactured as a liquid, cream or aerosol. Absorbed in large doses, it is fatal after 15 minutes, according to the US Army's Edgewood Chemical Biological Center, making it the most toxic known nerve agent in the world.

Jong-nam died at KLIA2 airport terminal on Feb 13 after two unidentified women had purportedly sprayed or wiped his face with a liquid that had left him feeling ill.