Business seller withheld key information that would have stopped the sale of their business. What is the buyer's recourse? 

Specifically, a significant increase in claims several months leading up to the sale against the purchased company has significantly damaged the company's reputation and ability to generate revenue after the sale.  Buyer repeatedly requested claim data and was told "virtually no claims."  Owner came in to clean up "the only two claims" left open which were shown to buyer upon request.  However, buyer found 64 additional claims from before the sale that were not addressed.  These claims have significantly damaged the reputation of the business resulting in a sharp, significant decrease in sales and potential bankruptcy.