Traders from banks, oil companies or hedge funds have an “incentive” to distort the market and are likely to try to report false prices, it said.

Politicians and fuel campaigners last night urged the Government to expand its inquiry into the Libor scandal to see whether oil prices have also been falsely pushed up.

They warned any efforts to rig the oil price would affect how much drivers pay at the pump, which soared to a record high of 137p per litre of unleaded earlier this year.