The National Fraud Initiative has passed the £1bn mark in detected rackets and mistakes.
It was set up by the Audit Commission in 1996 and targets fraud, overpayment or payment errors.
The commission said the initiative had prevented or detected almost 100,000 cases of wrongly claimed council tax single person discounts, worth £160m, and more than £250m of housing benefit overpayments.
It also said 68,736 blue badges and 97,361 concessionary travel passes had been cancelled as a result of investigators’ work.
The initiative compares data from 1,300 public sector bodies and 77 private sector one and flags up inconsistencies that potentially indicate fraud including, for example, if activities are repeated over a large geographical area or are masked by false identities.
Commission chair Jeremy Newman, said: “The vigilance of organisations from local councils to central government departments, supplying essential data and investigating potential frauds flagged up by the initiative, has paid off to the tune of £1bn.
“We are working hard to ensure this valuable legacy of the Audit Commission continues to benefit the public.”
The Department for Communities and Local Government is yet to decide where the NFI will be placed once the commission is abolished in Spring 2015.