German prosecutors have raided Audi and VW sites on Wednesday in connection with the emissions scandal. This adds to the pressure on the luxury division and Audi chief executive Rupert Stadler.

The officers have raided the Audi plant in Ingolstadt, Bavaria and eight other sites that include parent company VW headquarters in Wolfsburg. Munich prosecutors claim the raids were carried out in order to identify those involved in installing the devices that cheated the diesel test, as reported by BBC. Audi-owner VW has already promised to pay $21 billion worth of settlements in the US.

"With these search orders we aim to clarify in particular who was involved in deploying the technology concerned and in the provision of false information to third parties," the Munich prosecutor's office said in a statement on Wednesday, without naming any suspects. German prosecutors from three states add that the raids in the Audi and VW sites were part and parcel of a US emission tests probe. According to them, buyers of some 80,000 V6 3.0-litre Audi and VW diesel cars that were sold in the US from 2009 to 2015 were unaware of the emissions scandal.

Reports note that the police swoop coincided with a major annual press conference at which Audi CEO Stadler was presenting the company's 2016 earnings. Stadler has run Audi since 2007 and has long been criticized for mishandling the emissions scandal but claims command of the VW board's full support. Sources, on the other hand, claim that Stadler's home was not among those searched.

In a statement, Audi expresses its interest in getting to the bottom of the emission-cheating scandal and vows to fully cooperate with the raids. Meanwhile, the prosecutors stress that cars sold in European markets are outside the scope of the investigation. Last year, Audi increased its diesel scandal-related provisions to 1.63 billion euros as per Reuters.