A number of Porsche and Audi facilities have been raided by German prosecutors as part of ongoing investigations related to the diesel emissions cheating scandal.

Thirty public prosecutors searched ten Porsche properties in search of unspecified documents. Financial Times reports that three people have come under suspicion after the raid, including a member of the Porsche management board, a senior Porsche manager, and a former Porsche employee.

In a statement, Porsche confirmed that the inspections had taken place but remained coy on details.

“We confirm that investigators today inspected and secured documents at the offices of Porsche AG in Stuttgart and Audi AG in Ingolstadt. Audi AG and Porsche AG are co-operating fully with the investigating authorities. Please appreciate that we can’t comment on further details due to the ongoing investigation.”

Two sources from Volkswagen claim that the raids are unrelated to recent changes within the company, including chief executive Matthias Muller being replaced by VW passenger car head Herbert Diess. The head of Porsche, Oliver Blume, was also promoted to the VW Group’s management board.

Stuttgart prosecutors say they received help from counterparts in Munich in conducting these investigations which also saw the arrest of Wolfgang Hatz, a former VW Group executive, last year.