The Swiss Office of the Attorney General "has meanwhile opened a criminal investigation and carried out measures to secure evidence from the AMAG Group. AMAG cooperated fully with the law enforcement authorities," the OAG said in a statement.

Swiss regional prosecutors had agreed last year to collect and forward to German counterparts all criminal complaints filed in Switzerland in connection with the manipulation of VW exhaust emission data. They had sent around 2,000 criminal complaints to Germany before the court ruling.

(Reporting by Michael Shields; editing by Brenna Hughes Neghaiwi)