Malaysian police have said the chemical substance used in the killing of Kim Jong-nam was a “VX nerve agent”, a type of chemical weapon.

The finding follows a preliminary analysis of facial and eye swabs of the victim, who is the half-brother of North Korean leader Kim Jong-un.

The highly toxic substance – also known as ethyl N-2-Diisopropylaminoethyl Methylphosphonothiolate – is classified by the United Nations as a weapon of mass destruction.

Malaysian police said its Centre for Chemical Weapons was still analysing other items.