The court officials overseeing the NFL’s $1 billion settlement fund for concussion-related injuries have barred five law firms from handling any more claims from former players, after finding that they fraudulently steered clients toward doctors willing to give them a Parkinson’s disease diagnosis whether they exhibited symptoms or not.

The five firms represented or performed work involving 98 former players who in recent years sought six- to seven-figure payouts from the settlement for Parkinson’s disease claims, the special masters appointed to help oversee the settlement wrote in a report filed Monday in U.S. District Court in Philadelphia.