The U.K.’s Serious Fraud Office (SFO) is looking into suspicions that JJB Sports and Sports Direct fixed prices while Chris Ronnie ran JJB. The Office of Fair Trading (OFT) has been investigating the possibility of price-fixing and fraud by these two major British sporting goods retailers since January, and it has referred the complaint on to the SFO, which is conducting its investigation parallel to the OFT.

JJB Sports itself approached the OFT last Jan. 30 to inform the British agency about the suspected anti-competive activities, while asking for immunity from any financial penalties that may acrrue from the findings of its investigations, in line with the OFT’s special leniency program.

The approach to the OFT was made by JJB 11 days after its board of directors “suspended” Ronnie from his functions as chief executive. Ronnie, who had been previously acting as Mike Ashley’s right-hand man at Sports Direct, joined JJB in the summer of 2007 and left the company completely at the end of last March. JJB has told the OFT that the suspected price fixing occurred between June 8, 2007 and March 25, 2009, coinciding with Ronnie’s tenure at the company.

JJB said in a statement today that it is working closely and cooperating with the British government on the case. Should the OFT decide that the company has not been cooperating with the investigation, the immunity would be lifted and the company could be subject to fines of as much as 10 percent of turnover. Sports Direct also said in a subsequent statement today that it was cooperating fully with the investigation, but added that it had no further comment.

The OFT said that it had executed searches at two addresses, without specifying where; however, JJB and Sports Direct said that OFT officers visited their respective offices in Wigan and Shirebrook today.

Price fixing has been a criminal offense in the U.K. since 2002, and could garner jail time for any offenders. JJB had to pay a big fine a few years ago on a charge of price fixing in the sale of England football jerseys under a previous investigation launched by the OFT after it was tipped off by Ashley when his chain was called Sports Soccer.