More than two-thirds of the fiscal 2009 spending data reported to USASpending.gov was flawed or late, according to an analysis by the Sunlight Foundation, an open government group that has created an online scorecard to highlight the performance of individual agencies.

"As long as such a large portion of its data remains unreliable, USASpending.gov is not usable as a single source for any kind of analysis, whether by a citizen, media outlet or research institution," the report says.

"The government keeps building new sites on top of this site even though they know the data is inaccurate," foundation spokeswoman Gabriela Schneider added in an interview.

The USASpending.gov site is maintained by the Office of Management and Budget, which is already working with agencies "to ensure data quality and completeness," Communications Director Kenneth Baer said in an e-mail. The Obama administration has put out two memos on the subject this year, Baer said, and OMB will be publishing more guidance this fall.

Last year, some 70 percent of the data on $1.9 trillion in obligations that federal agencies reported to USASpending.gov was either inaccurate, incomplete or reported late, the Sunlight Foundation concluded. The Federal Direct Student Loan Program, for example, claimed more than $5 trillion in loans — a figure that far exceeded last year's federal budget. In general, smaller agencies such as the National Endowment for the Arts, performed better than larger shops such as the Veterans Affairs Department, the review found.

Under the 2006 Federal Funding Accountability and Transparency Act, co-sponsored by then-Sen. Barack Obama, D-Ill., agencies are supposed to report new spending within 30 days after its obligation. In fiscal 2009, only one-third of the reported data came in on that timetable.