German prosecutors have filed charges against former Audi chief executive Rupert Stadler, who is being investigated over his alleged role in Volkswagen’s emissions test cheating scandal.

Porsche is bracing for smaller profit gains in future as Volkswagen’s sports-car division steps up spending on models and facilities, chief executive Oliver Blume said.

German prosecutors have launched an investigation into fraud allegations against former Volkswagen boss Martin Winterkorn over the carmaker’s rigging of diesel emissions tests.