A Buffalo attorney is taking on more than 50 insurance companies in an unusual whistleblower case that seeks hundreds of millions of dollars for the federal government—and a hefty share for himself.

Attorney J. Michael Hayes’ False Claims Act case came to light this week after the Western District U.S. Attorney declined to intervene, and a judge unsealed his qui tam complaint accusing several dozen insurance companies of failing to repay Medicare after settling personal injury cases on behalf of their clients. With the government on the sidelines, Hayes could collect up to 30 percent of any recovery, plus legal fees and expenses.