How police are catching drug-drivers at the roadside

More than 2,500 motorists in Wales have been caught driving under the influence of drugs since new police powers were introduced three years ago.

The majority of drug-drivers were stopped by North Wales Police, with 1,029 people arrested, figures obtained by the BBC show.

They were asked to take a roadside test, which identifies drugs including cannabis and cocaine.

Gwent Police caught 662 drivers, South Wales Police 575 and Dyfed-Powys 262.

Sgt Huw O'Connell, of South Wales Police's roads policing unit, shows how "drugalysers" work to catch drug drivers.