Speaking to Bild, Transport Minister Alexander Dobrindt said: “There will be controls for motor vehicles in the style of doping tests. Unannounced, every year.”

He added that the tests would help restore confidence in the car industry in the wake of the emissions scandal.

A draft proposal on the new measures is currently being presented, with Mr Dobrindt saying that other planned measures include more rotation of the inspection services and the disclosure of the engine software.