Two top managers from Audi and Porsche are allegedly set to leave their posts Friday amid continuing controversy over Volkswagen diesel cars that reportedly cheated on emissions road tests in the United States to appear more environmentally friendly. Both car companies are owned by Volkswagen, and leading development executives Ulrich Hackenberg of Audi and Wolfgang Hatz of Porsche will be forced out at a meeting Friday, the German newspaper Bild reported Thursday.

Both Hackenberg and Hatz were two of the top-ranking engineers at the company, and their dismissal has come as Volkswagen attempts to clear its ranks of employees implicated in the current scandal. Martin Winterkorn, the chief executive officer, resigned Wednesday.

Winterkorn said he was not aware of the emissions irregularities, though he still took full responsibility as CEO in his statement of resignation Wednesday. "I am shocked by the events of the past few days. Above all, I am stunned that misconduct on such a scale was possible in the Volkswagen Group," read the statement published on Volkswagen's website. "Volkswagen needs a fresh start – also in terms of personnel. I am clearing the way for this fresh start with my resignation," Winterkorn wrote in the same statement.

News that Hatz and Hackenberg were leaving came as German transport minister, Alexander Dobrindt, accused Volkswagen of manipulating emissions tests not only in the U.S. but in Europe as well. “We will therefore continue to work intensively, together with Volkswagen, to find out exactly which vehicles are involved,” said Dobrindt Thursday, as reported by the Financial Times.

Nearly 11 million cars have been affected by the misleading software, causing uproar among Volkswagen owners and environmental protection agencies alike. The company first estimated Friday that 500,000 cars had been affected. Volkswagen issued a recall for all cars that were affected, which range from diesel-run Jettas to Audis to Beetles, and customers worldwide have demanded refunds or financial restitution. 

The Environmental Protection Agency has begun a probe into Volkswagen, and several affected customers have already filed civil suits against the company.