A VAN driver in Dumbarton allegedly failed a roadside drug test after police detected the 'unmistakable' smell of cannabis coming from the vehicle during a road stop.

The Ford Transit was pulled over by road officers on the A814 on Monday due to having a light out.

And, due to the reported distinctive stench of the herbal class B drug emanating from within the van, cops decided to drug test the 26-year-old female driver.

The drug wipe for cannabis and cocaine was allegedly failed.

A report has been passed to the Procurator Fiscal.