Lenders taking advantage of a loophole in the federal student-loan program may have improperly collected more than twice the $300-million in overpayments already identified by Education Department auditors, The Washington Post reported.

The Post, in an analysis of subsidy-payment records released this past summer, said a group of 10 lenders collected “as much as $330-million in potential overpayments” beyond the amount to which they should have been legally entitled.

The department’s inspector general concluded last year that one other lender, Nebraska-based Nelnet, collected $278-million in improper overpayments by manipulating a program that once made lenders eligible, years earlier, for a 9.5-percent interest rate.

The department later forgave a total of $322-million, including amounts received after the time of the inspector general’s audit, as part of a settlement in which Nelnet agreed to stop billing for loans at the old 9.5-percent rate.

The Chronicle, in a report last month on the same payment records, said that total federal subsidy payments to nonprofit lenders under the 9.5-percent loan program exceeded $3.5-billion between 2001 and 2006. The Post’s reported figure of $330-million, on top of the Nelnet figure, represented an attempt to calculate how much of that 9.5-percent billing was “improper,” using the criteria that the inspector general applied in the Nelnet case.

The Post’s report also included an interview with the education secretary, Margaret Spellings, in which she said the federal government “had some responsibility” for creating “confusion” over the 9.5-percent subsidy rules. But Ms. Spellings told the Post that she still had no plans to seek reimbursement from the lenders, despite pressure in Congress that she do so, and had no plans to pursue a full accounting of exactly how much was lost. —Paul Basken