Kim Jong-nam died after nerve agent was smeared in his face at Kuala Lumpur airport

The eldest brother of Kim Jong-un, who was assassinated with nerve gas by North Korean agents, was an informant for the CIA, according to a new book which also claims that he laundered counterfeit money through casinos and associated with gangsters.

The revelations cast new light on the mysterious life of Kim Jong-nam — the half-brother of the supreme leader — and go some way to explain his agonising and public murder in 2017.

Mr Kim died after being smeared on the face with VX nerve agent at Kuala Lumpur airport in Malaysia as he prepared to fly back to Macau.

Two women — one from Indonesia, the other Vietnamese — were tricked by North Korean agents into carrying out the attack in the