The Office of Fair Trading (OFT) issued a statement which said it was "investigating suspected cartel activity involving commercial vehicle manufacturers in the UK." It added that investigations were at an early stage and had yet to conclude whether any laws had been broken.
An OFT spokeswoman also confirmed newspaper reports that British offices of Mercedes-Benz, owned by German vehicle giant Daimler, had been raided earlier
She added that one person had been arrested and released on bail, although it was not clear whether he or she worked for Mercedes.
MAN, as well as Swedish truckmakers Scania and Volvo, told AFP that they had been asked to provide the OFT with information regarding the probe. Fiat-owned Iveco added that it was ready to cooperate fully after becoming aware of the investigation "implicating the bulk" of truckmakers.
Companies involved in British price-fixing can be fined up to 10 percent of their annual turnover, while executives face prison sentences.