An apartment in an upscale Kuala Lumpur suburb was reportedly raided by authorities on Wednesday (February 22) in search for the chemical used in the murder of North Korean Kim Jong Nam, said an official with direct knowledge of the matter.

A visitor of the apartment told reporters outside the building that he saw police officers at the premises earlier this week.

VX nerve agent, a chemical on a United Nations list of weapons of mass destruction, was used to kill the estranged half-brother of North Korean leader Kim Jong Un in last week's bizarre assassination in a busy Kuala Lumpur airport, police said on Friday (February 24).

Two female suspects, an Indonesian and a Vietnamese, have been arrested by Malaysian police while at least five more remain at large.