Lawyers were overpaid by more than £50m for legal aid work last year, auditors have found.
The National Audit Office cited the huge errors as it refused to give the Legal Services Commission’s accounts a clean bill of health.
Some £29.5m of the excess was down to law firms claiming too much for work, while the remaining £21.2m related to cases where individuals were not eligible for aid.
The spending regulator stressed that the overpayments had dropped by a third since 2009-10, when they were estimated at £76.5m.
However, as well as qualifying the books, Auditor General Amyas Morse also highlighted problems with estimates of how much was owed by people receiving legal aid.
Mr Morse said: “While the Legal Services Commission has made considerable progress, it still faces difficulties in reducing the level of error in payments to legal services providers.
“The Commission also needs to make significant improvements to the quality of the data supporting the reported balance of outstanding debt.
“In an environment of spending cuts, the Commission will need to make difficult decisions on the costs and benefits of further work to improve in these areas.”
The Legal Services Commission provides legal aid for civil and criminal cases in England and Wales through the Community Legal Service Fund and the Criminal Defence Service.