Volkswagen has condemned searches carried out by German prosecutors into the US law firm hired by the carmaker to investigate the emissions scandal.

According to reports, police took part in searches at several sites across Germany.

German paper Handelsblatt reported the searches were ordered by the prosecutor’s office in Munich of its probe into Volkswagen’s role handling a cover up of systematic emissions cheating.

According to reports, around 100 police took part in searches Wednesday at Audi’s Ingolstadt and Neckarsulm sites as well as seven other locations across Germany, including the brand’s office in Wolfsburg.

In response, Volkswagen said: “We consider the action of the Public Prosecutor’s Office in Munich to be unacceptable in every respect. In our opinion, a search carried out on the premises of a law firm which has been instructed by a company is a clear breach of the principles of the rule of law laid down in the Code of Criminal Procedure. This has also been expressly confirmed by the Federal Constitutional Court in the case of another law firm.

“We will take all the action at our disposal against these proceedings.”