BERLIN – Prosecutors in Germany said Friday they are expanding their probe into Volkswagen’s scandal over diesel cars that cheated on emissions tests.
As well as increasing the number of suspects, prosecutors said they have evidence former CEO Martin Winterkorn may have known of the cheating earlier than he has claimed.
The prosecutor’s office in Braunschweig, near Volkswagen’s Wolfsburg headquarters, also said Winterkorn was now being investigated on suspicion of fraud, beyond an earlier focus on a possible securities-market violation.
The announcement raises the legal stakes for the former head of Germany’s largest automaker. The 69-year-old stepped down in September 2015, days after news emerged in the U.S. of Volkswagen’s use of software that turned off emissions controls. He said at the time that he was not aware of any wrongdoing on his part.
He testified before a parliamentary committee last week that he first heard the term “defeat device,” the technical name for the illegal software, in September 2015 – even though U.S. authorities had been pressing Volkswagen for months over emissions test discrepancies and the cheating had been going for several years.

