Police in Malaysia say a powerful nerve agent called VX appears to have been used in last week’s killing of Kim Jong-nam, the half brother of North Korean dictator Kim Jong-Un.

The police chief earlier suggested sending a group of forensic experts to the airport to test for any signs of contamination.

The BBC's Rupert Wingfield-Hayes went there to trace the footsteps taken by Kim Jong-nam when he was attacked at the airport.