Conservative MP Robert Halfon who has led a campaign calling for a full investigation into alleged cartels and market manipulation in the oil market for the past three years, said:
Last year, in a debate that I pressed for, Parliament voted unanimously for an investigation into the oil market.
These latest allegations underline why that must happen urgently in the UK.
High oil prices are crushing families across Britain. Motorists are being taken for a very expensive ride.
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.
Mr Halfon told BBC Radio 4's Today programme anyone found guilty of price fixing should face jail and oil firms should expect hefty fines:
Clearly there has been a problem, there needs to be a full inquiry.
The Government needs to say, anyone caught doing this, there should be prison for price fixing and there should be huge multimillion-pound fines on any oil company found guilty and that money should be passed back to the motorist.