Volkswagen can take a sigh of relief as it appears the current CEO, Matthias Müller, didn't have any prior knowledge of the diesel emission cheating. German newspaper Bild am Sonntag (via Reuters) got their hands on a report done by Jones Day which said Müller didn't find out the scandal till the EPA made the announcement - September 18, 2015 if you're wondering. Only a week later, Müller would be named CEO of Volkswagen.
Still, Müller's track record on dealing with the diesel emission mess is spotty. He has said the scandal was just a 'technical problem' and a misunderstanding about U.S. law - claims that were deemed false and got Müller in hot water.
Source: Bild am Sonntag via Reuters