Italian police on Thursday raided Volkswagen's main office in the country and those of its sports car unit Lamborghini in connection with the investigation into the company's rigging of emissions tests.

Six Italian-based executives of the group were placed under investigation, including VW Italy's CEO Massimo Nordio and Luca De Meo, the marketing and sales chief of the Italian branch of Audi, another VW company, the AGI news agency reported.