German prosecutors said Wednesday they had charged former Audi chief executive Rupert Stadler with fraud over the Volkswagen subsidiary's role in the "dieselgate" emissions cheating scandal.
"Professor Rupert Stadler and three other defendants... are accused of fraud, falsifying certifications and illegal advertising," the prosecutors in Munich said.
The charges are linked to over 430,000 VW, Audi and Porsche cars fitted with "defeat devices" to fool regulators' emissions tests.
Such software, applied to diesel-fueled cars, allows the vehicles to detect when they are being tested in the lab and reduce harmful emissions far below actual levels released on the road.
Stadler found out "at the latest in September 2015," when Volkswagen admitted to selling 11 million cheating vehicles worldwide after an American investigation.
But from that time on, Stadler knowingly continued selling affected vehicles from Audi especially in Europe and the U.S., prosecutors say.
Porsche and VW cars fitted with cheating engines from the high-end subsidiary also continued rolling out of dealerships.
The charges relate to sales of 250,712 Audi cars, 71,577 Volkswagens and 112,131 Porsches.
Sprawling 12-brand group Volkswagen has so far been hit with over 30 billion euros ($33.5 billion) of costs relating to dieselgate, much of it for fines, buybacks and compensation payouts in the U.S.
The scandal has jolted the German auto industry as other car manufacturers like Mercedes-Benz maker Daimler have found themselves accused of similar cheating.
VW is making a massive shift to electric vehicles partly in response, while German politics was for much of 2018 consumed with debate over whether and how to ban the most polluting diesel vehicles from city centers.