A new invention is bringing police a step closer to performing drug tests on drivers

Police and scientists have developed a handheld device to test for - methamphetamine, MDMA and cocaine.

A six-month trial will be carried out in the Auckland, Canterbury and Central police districts.

The Government announced in December it would give police powers to conduct random roadside drug tests, and prosecute drugged drivers.

The oral fluid testing rules should come into force next year, with guilty drivers fined and suspended from driving for 12 hours.