BERLIN — Audi’s head of technical development, Stefan Knirsch, is leaving his job immediately, the carmaker said on Monday, as investigations continue into a diesel emissions scandal facing its corporate parent, Volkswagen.
An investigation by the American law firm Jones Day, which was hired last year by VW’s supervisory board to look into the scandal, found no evidence of wrongdoing by Audi’s chief executive, Rupert Stadler. But the departure of Mr. Knirsch, who had been Audi’s head of engine and transmission development, adds to concerns that VW’s flagship luxury brand may be more deeply entangled in the scandal than previously thought.
Audi said in a statement that Mr. Knirsch was leaving immediately in consultation with the supervisory board. It cited no reason for his departure, and it did not name a successor.
Mr. Knirsch and Jones Day representatives in Germany did not immediately respond to requests for comment.
“We have made clear from the start that we have no regard for big names and take action if necessary” to try to resolve the scandal, Audi’s deputy chairman, Berthold Huber, said in a separate statement on behalf of the 10 labor representatives on Audi’s 20-member supervisory board.
“This departure underlines our position,” Mr. Huber said.
Audi, the main contributor to VW’s profit, has admitted that its 3.0 liter V6 diesel engine was fitted with software that reduced the amount of pollutants emitted in tests, compared with normal road conditions. The software is illegal in the United States, where VW’s emissions scandal broke a year ago.
Mr. Knirsch was appointed in January, replacing Ulrich Hackenberg, the former top engineer at Audi and the VW group. Mr. Hackenberg quit last year after being suspended with two other executives closely associated with the development of the VW engine at the center of the scandal.
Mr. Knirsch is the fourth head of research and development that Audi has lost in four years, at a time when the carmaker is battling with German rivals such as BMW and Mercedes-Benz for leadership in developing new technologies.