BP and Shell offices are raided by inspectors after allegations of collusion over price-fixing, which regulators say may have pushed up the price of petrol over the last ten years.
BP, Shell and the Norwegian company Statoil all confirmed that their offices were inspected by officials from the European Commission on Tuesday.
MPs and motoring group have called for UK regulators to investigate amid concerns of consumers being conned.
In a statement, the European Commission said that even small distortions of assessed prices could have a “huge impact on the prices of crude oil, refined oil products and biofuels purchases and sales, potentially harming final consumers”.
Speaking in the House of Commons, Energy Secretary Ed Davey said:
“This government is deeply concerned that prices for consumers could have been artificially or unneccessarily driven up”, but he added that “the Commission has made clear that investigations do not imply guilt.”
Mr Davey urged the companies involved to co-operate with the investigating authorities and said that the Office of Fair Trading (OFT) would be providing the EU with any assistance it required to complete its inquiry.
Collusion over price-fixing may be a violation of EU rules, as well as influencing prices that consumers pay.
High oil prices are crushing families across Britain. Motorists are being taken for a very expensive ride. Tory MP Robert Halfon
Both Shell and BP confirmed that offices were inspected and said that they were co-operating fully with the investigation.
Tory MP Robert Halfon, who leads a campaign calling for a full investigation into alleged cartels and market manipulation in the oil market, said the allegations underline the need for a UK investigation.
“High oil prices are crushing families across Britain. Motorists are being taken for a very expensive ride,” he said.
“The government has done its bit, by freezing fuel duty for three years. Now oil companies must come clean and show some responsibility for what is happening to the international oil price.”
The European Commission confirmed that officials carried out unannounced inspections on Tuesday.
“The commission has concerns that the companies may have colluded in reporting distorted prices to a Price Reporting Agency to manipulate the published prices for a number of oil and biofuel products,” the statement read.
“Furthermore, the commission has concerns that the companies may have prevented others from participating in the price assessment process, with a view to distorting published prices.”
Speaking at prime minister’s questions, the Deputy Prime Minister Nick Clegg said that “large oil companies should, of course, co-operate with the EU commission.”
RAC technical director David Bizley said the allegations were “worrying news for motorists” who are already suffering due to the high cost of keeping a vehicle.
Energy Secretary Ed Davey said “it is in our mutual interest for motorists and businesses to be confident they are being treated fairly, and when wholesale prices come down these reductions are passed on transparently and without unneccessary delay.”
The European Commission said that unannounced inspections are a preliminary step to investigating suspected anti-competitive practices and do not mean that the companies are guilty of any wrongdoing. There is no legal deadline to complete inquiries, it added.