Firms that are paid tens of millions of dollars to root out Medicare fraud are bidding on contracts to investigate companies they are doing business with—sometimes their own parent companies, according to a government report released Tuesday. Two-thirds of the companies that bid on contracts during a nearly year-and-a-half time period beginning in October of 2010 had financial ties to claims processors—and in some cases also processed Medicare claims themselves, according to the study by the U.S. Department of Health and Human Services' inspector-general.