VW chief met FBI over emission scam, obtained guarantees:Reports

Volkswagen chief Herbert Diess met FBI investigators over the diesel emissions cheating scandal and secured guarantees from Washington days before US authorities indicted his predecessor, German media reported today.

Diess reportedly travelled to the United States on May 1 and gave statements to investigators from the FBI and justice department that are "apparently rated as incriminatory" for ex-VW chief Martin Winterkorn, Bild daily said, quoting unnamed sources.

Winterkorn's indictment on May 3 has brought the US criminal case to the top echelons of Volkswagen, which pleaded guilty last year to lying to American environmental regulators about emission control systems.

Winterkorn faces four counts, including conspiracy to defraud the US and wire fraud.

American prosecutors say Winterkorn knew of the company's emissions cheating as early as May 2014 but decided to continue with the fraud, the Justice Department said in a statement.

While Winterkorn cannot leave Germany due to the threat of an arrest on an international warrant, Diess has managed to obtain assurances that he is free to travel to the US and elsewhere, German media reported.