The murder of North Korean leader Kim Jong-un’s half brother Jong-nam at the KL International Airport has led to many theories on the method that was employed.

Multiple South Korea media reports claimed that sources from their government believed that Jong-nam was "poisoned with a needle".

The Australian Broadcasting Corporation, quoting sources with the US government, could not rule out the possibility that some sort of "poison pen" device was involved.

According to Oriental Daily, quoting police sources, a poison "more powerful than cyanide" was applied on Jong-nam through a spraying device.

Yesterday, Berita Harian quoted Selangor police chief Abdul Samah Mat as stating that initial reports indicated that the assassins covered Jong-nam's face with a liquid-soaked cloth.

This caused the victim's eyes to sting and he was pronounced dead en route to the Putrajaya Hospital.

There are also disputes on the identity of the assassins.

Foreign news agencies are claiming that the assassins were North Korean agents, a theory shared by the South Korean government.

Jong-nam's cousin Lee Han-young defected through Switzerland in 1982 and was murdered by North Korean agents while in Seoul in 1997, according to South Korea.

However, Oriental Daily, citing police sources, claimed that the alleged assasins had told the driver of the taxi which they boarded at KLIA after the incident that they were Vietnamese.

What has been established so far is that the alleged assassins had approached Jong-nam on Monday morning, before he was supposed to board a flight to Macau.

Various local news reports today claimed that the assassins could be clearly seen through CCTV footages.

Inspector-general of police Khalid Abu Bakar has confirmed that the 46-year-old man held a passport under the name Kim Chol.