The European Commission has launched surprise checks at tyre manufacturers across several member states, investigating potential price fixing and cartel activity.

The inspections will probe whether new replacement tyres for passenger cars, vans, trucks, and buses sold within the European Economic Area have been subject to market collusion - possibly through media advertising – which breaks EU antitrust rules.

Commission investigators were joined by their counterparts from national competition authorities in what could be the first step into action to tackle suspected anticompetitive practices and cartel activity.

It said such inspections neither imply guilt nor prejudge the ultimate outcome of the investigation adding that inquiries into anticompetitive conduct do not have a set legal deadline and that their duration will depend on the complexity of each case and the level of cooperation from the companies under investigation.

The European Commission said any business operating a secret cartel may be granted immunity from fines or receive significant reductions in fines in exchange for reporting the conduct even anonymously, through the Commission's whistle-blower channels.

Nokian Tyres, headquartered in Nokia, Finland, said in a statement that it was fully co-operating with the authorities after receiving an unannounced inspection.

“Nokian Tyres does not have information on the outcome of the inspection, and it cannot comment on the ongoing investigation,” it said.

Italian company Pirelli told Reuters it had acted fairly and "always in total compliance with all rules and regulations".

"Pirelli informs that it is guaranteeing full support to the authority in the ongoing investigations," a spokesman for the Milan-based company said.

German rival Continental confirmed that investigations by European antitrust authorities were taking place at the company's offices in Germany.

France's Michelin said it was included in the EU investigation and that it strictly complies with competition rules.