The half brother of North Korea’s leader was allegedly assassinated using a substance known as “VX nerve agent”, Malaysian police have said.

Kim Jong-nam, the half brother of North Korean leader Kim Jong-un, died last week shortly after two women put a substance on his face while he was checking in for a flight.

On Friday, police said initial findings from the Chemistry Department of Malaysia pointed to the use of “VX nerve agent”, a tasteless, odourless substance used in chemical warfare.

It is not known how the women were able to apply the nerve agent to Mr Kim’s face without becoming ill themselves.

Police have not said if they wore thin gloves or if washing their hands after using the agent had removed the danger.

What is VX?

VX nerve agent was developed in the 1950s in the UK and is an oily liquid that is amber in colour and slow to evaporate, according to the United States’ Centers for Disease Control and Prevention.

It is classified as a nerve agent, which are “the most toxic and rapidly acting of the known chemical warfare agents”.

Bruce Goldberger, a leading toxicologist who heads the forensic medicine division at the University of Florida, said protective measures would have been needed if the two women handled the agent without wearing gloves.

“It’s also possible that the toxin was encapsulated, then activated when applied to the skin,” he told Associated Press.

Kim Jong-nam collapsed before having gone through immigration. Photo: AP

On Thursday, Malaysia’s police chief said investigators wanted to question a North Korean embassy official about Kim Jong-nam’s death, saying he should co-operate if he has nothing to hide despite having diplomatic immunity.

Inspector-General of Police Khalid Abu Bakar said police have also asked Interpol to issue an alert for four North Korean men who left Malaysia the same day Kim Jong-nam was attacked by the two women.

The four men are believed to be back in North Korea, but police also want to question three other people still in Malaysia, including Hyon Kwang Song, a second secretary at the North Korean Embassy.

Kim Jong Nam is the half brother of North Korean leader Kim Jong-un ‘. Photo: Getty

“The foreign officer has got immunity so we have to follow protocol,” Khalid told reporters. “If you have nothing to hide, you don’t have to be afraid. You should co-operate.”

The two suspected attackers, and Indonesian woman and a Vietnamese woman, are in custody.

Pop Idol suspect

Meanwhile, police have also revealed on of the women, Doan Thi Huong, 28, worked in Malaysia’s entertainment industry.

It is also believed that she was a contestant on theVietnam Idol talent show.

Facial recognition technology was used to match Ms Huong to a woman who appeared on the show under a different name in June last year, Reuters reported.

It has also been suggested Ms Doan and Indonesian woman Siti Aisyah were tricked into believing they were appearing on the prank television program show Just for Laughs, a claim rejected by police.

https://www.youtube.com/watch?v=vCvi1jiyOaA