A PLYMOUTH man has been arrested on the M5 after a police stop-search on the motorway uncovered 1.5 kilos of powder, believed to be heroin.

​At around 2.30pm yesterday members of the road crime unit stopped a Ford Focus car on the M5 travelling towards Exeter.

The driver, a 38-year-old man was detained after he was seen to swallow an item.

A subsequent search of his vehicle revealed powder suspected to be heroin, a class A controlled drug.

The weight is about 1.5 kilos with an estimated street value in excess of £90,000.

The man, who is from the Plymouth area, was arrested and is assisting police with their enquiries at Exeter police station.