The North Korean being held over the murder of Kim Jong-nam has a doctorate in chemistry and is suspected of arranging all the logistics for the attack in Kuala Lumpur, the Telegraph can reveal.

The new details came as CCTV footage emerged showing the attack that killed the half-brother of Kim Jong-un, the North Korean dictator.

Mr Kim died last Monday a short time after the attack in the departure hall of Kuala Lumpur International Airport.