FRANKFURT, Germany (AP) — German prosecutors have charged the former head of Audi, Volkswagen's luxury division, with fraud in connection with sales of diesel cars with software that enabled cheating on emissions tests.

Prosecutors in Munich said in a news release Wednesday that they had charged Rupert Stadler and three other individuals. The three unnamed individuals were charged with having developed engines used in Audi, Volkswagen and Porsche models that had software that made the emissions controls work better on the test stand than in real-life driving.

Stadler was charged with having known about the manipulation in Audi and Volkswagen cars and with continuing to sell the models despite that knowledge.

Volkswagen admitted the cheating in 2015 and paid billions in fines and settlements while two executives went to prison in the U.S.