British investigators say they are "urgently reviewing" whether to join an EU investigation of three oil companies for alleged gasoline price-fixing.

A spokesman for Britain's Serious Fraud Office told The Telegraph Friday the agency will decide shortly whether it will join the European Commission's directorate general for competition in probing BP, Shell and Norway's Statoil for alleged collusion in the British gasoline market.

"Subject to discussions with other agencies as to the potential offenses involved, it is likely that the SFO could be the appropriate authority to investigate allegations of price-fixing," the spokesman said.

"We are urgently reviewing the matter and would expect to announce any decision to accept the case for criminal investigation if and when such a decision is made."

British Energy Secretary Edward Davey announced in Parliament last week the European Union was looking into possible price-fixing by the companies, only months after Britain's own Office of Fair Trading had assured the public the gasoline market was "working well."

Gas prices at the British pump have gone up 60 percent since 2009 to around $4.30 per U.S. gallon.

Davey told the House of Commons the European Union has concerns the three 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.

"Any such behavior, if established, may amount to violations of European antitrust rules that prohibit cartels and restrictive business practices and abuses of a dominant market position," he said.

"This government (is) deeply concerned by any allegation that prices for consumers could have been artificially or unnecessarily driven up. The U.K. government and regulators will provide any assistance necessary to the European investigators, and we expect the companies concerned to fully comply with these investigations."

Davey cautioned, however, the investigation is at any early stage and that the investigation doesn't imply any guilt on the parts of BP, Shell and Statoil.

The late 2012 look at gas prices by the Office of Fair Trading didn't uncover evidence of higher gas prices due to manipulation of derivatives markets.

It did, however, did warn that such manipulation "is possible" and encouraged market players to blow the whistle if they had evidence of such practices.

Conservative Party Member of Parliament Robert Halfon, who has frequently spoken out about gas prices, demanded British regulators launch their own probe and said a whistleblower had indeed warned about gas price collusion but the allegations weren't properly followed up.

"Last year a motion for a full OFT inquiry into price-fixing by oil companies was passed unanimously in the House," he said. "We were approached by a whistleblower who suggested that the things we have seen over the past two days had been going on," but the allegations were only followed by a "limp-wristed, lettuce-like inquiry" rather than a full 18-month inquiry.

British Prime Minister David Cameron said Thursday that if the price-fixing allegations are borne out, he wanted to see prosecutions with the "full force of the law," The Telegraph reported.