German prosecutors are investigating current and former employees of Porsche, including a management board member, as part of their inquiries into emissions manipulations, Reuters reported.

Around 10 premises in Bavaria and Baden-Wuerttemberg were searched by around 160 officials, the prosecutor's office in Porsche's home town of Stuttgart said in a statement cited by the news agency.

"The three suspects include a member of the management board and a member of Porsche AG's higher management. The third suspect is no longer employed at Porsche AG," the statement said.

The searches form part of an investigation into Porsche AG employees suspected of fraud and fraudulent advertising tied to manipulated emissions control systems of diesel passenger cars, the prosecutors also said.

A Porsche spokesman confirmed the searches to Reuters but declined to provide further details.

Audi is also under scrutiny as its three litre, V6 diesel engine was used in about 80,000 VW, Audi and Porsche models found to have been equipped with illicit software, Reuters noted.

Two Audi sites were also searched on Wednesday, Stuttgart prosecutors and an Audi spokesman told the news agency. The searches were at Audi's sites in Ingolstadt and Neckarsulm, Audi said.