Washington, D.C. ? Whistle-blowers helped authorities recover at least $9.3 billion from health care providers accused of defrauding states and the federal government, according to an analysis of Justice Department records.

The department ramped up efforts in the 1990s to combat health care fraud by using private citizens with inside knowledge of wrongdoing. They now initiate more than 90 percent of the department’s lawsuits focusing on health care fraud.

Whistle-blowers start cases by filing a sealed complaint in federal court.

The department investigates the allegation and can intervene, assuming the lead role in the lawsuit.

Whistle-blowers then get between 15 percent and

25 percent of the amount recovered.

Of the $9.3 billion recovered between 1996 and 2005, whistle-blowers got more than $1 billion, say analysts, writing for the Annals of Internal Medicine.

The analysts’ findings are conservative. Information was only available for about three-quarters of the 379 cases reviewed. Second, some of the largest recoveries took place after the period reviewed.