Rupert Stadler is now officially under investigation by German authorities.

Audi CEO Rupert Stadler has been named by German police as under investigation for fraud and false advertising, Munich officials have confirmed. His apartment has been searched by police, according to the latest reports. 

The public prosecutor’s office in the city has widened the emissions investigation into the Volkswagen Group to cover 20 suspects, including another Audi board member. 

"Since May 30, 2018 the chairman of the board of Audi AG Rupert Stadler as well as a further member of the management board are now named suspects," the Munich prosecutor’s office said in a statement. 

To cap off a bad few days for the German executive, it was already revealed last week that a judge presiding over a lawsuit against Volkswagen by disgruntled shareholders had summoned Stadler and former Volkswagen CEO Martin Winterkorn to testify in the proceedings.

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Before he became CEO of Audi back in 2007 Stadler had previously worked as an assistant to ex-Volkswagen chairman Ferdinand Piech, who is part of the Porsche family that owns a controlling stake in the Volkswagen Group. 

He has enjoyed protection from the worst of the Dieselgate scandal thanks to his connections in the company, but it could be that the latest developments will make his position at the company untenable. He was appointed head of sales for the Volkswagen Group when new CEO Herbert Diess made some structural changes to management back in March 2018. 

Audi’s role in the emissions scandal emerged in November 2015, a matter of months after wrongdoing at Volkswagen was exposed. Audi developed and builds the VW Group’s 3-litre V6 diesel engine, which is one of the units which had defeat devices built in. It has seen action in everything from the Audi A4 to the Volkswagen Touareg and Porsche Cayenne.