The Federal Housing Finance Agency failed to address concerns about Freddie Mac‘s loan review process that may ultimately cost taxpayers billions of dollars, according to the FHFA’s inspector general. The Office of the Inspector General for the federal regulator said it raised concerns with managers at the government-sponsored enterprise about the review process throughout 2010. The examiner said Freddie Mac didn’t review more than 300,000 loans for possible repurchase claims because it only reviewed loans that had payment problems during the first two years after origination. Freddie’s own auditor raised similar concerns toward the end of 2010. But the FHFA didn’t take any action, and the inspector general believes “FHFA senior managers may have inaccurately estimated the risk of loss to Freddie Mac.” “By not reviewing intensively the mortgages foreclosed upon more than two years after origination for repurchase claims, Freddie Mac could potentially lose billions of dollars that could be used to mitigate taxpayer losses,” according to a report the inspector general released Tuesday. Freddie Mac senior managers disagreed with the examiner’s assessment, “at least partly because they believed a change to a more aggressive approach to repurchase claims would adversely affect Freddie Mac’s business relationships with Bank of America and other large loan sellers,” according to the report. In December, Bank of America (BAC) agreed to pay $1.35 billion to settle pending and future repurchase claims related to 787,000 loans it and its Countrywide unit sold to Freddie Mac. Bank of America also settled with Fannie Mae for $1.52 billion, regarding past and current repurchase claims. The inspector general reviewed the settlements because Congress questioned it, and the examiner believes the Freddie settlement may serve as a precedent for other deals with large financial institutions that sold loans to the GSE. The examiner recommends the FHFA address the concerns within the GSE loan review process and “promptly initiate management reforms to ensure more generally that senior management is apprised of and timely acts on significant concerns brought to its attention.” Last week, the inspector general said the FHFA lacks the staff to properly monitor the mortgage giants it has had in conservatorship since 2008. The report said the agency also failed to provide adequate oversight over default services legal issues. Write to Jason Philyaw. Follow him on Twitter: @jrphilyaw.