The U.S. Justice Department is in the early stages of investigating what authorities believe to be roughly $500 million in healthcare fraud perpetrated by companies that sell specialty creams designed to treat pain and other conditions, according to the Wall Street Journal. Retired NFL quarterback Brett Favre has heavily promoted Rx Pro, which is made by World Health Industries Inc., one of the firms being probed.

Topical pain creams have been heavily advertised to athletes, the elderly and the infirm in recent years, with the promise of relieving aches and cramping. But investigators are examining allegations that some of the most popular of these products have either little or no medicinal value, the Journal reported Saturday. Probers are also looking into whether some companies engaged in illegal business practices during their dealings with private and public insurers, including those run by the U.S. government. Some firms charged as much as $10,000 to fill a single prescription.

Tricare, the insurance program covering U.S. military personnel, veterans and their families, may have paid more than any other single victim of the alleged fraud, investigators told the Wall Street Journal. The program paid $1.75 billion for compounded drugs, including creams, during the 2015 fiscal year ending in September. That amount was 18 times the total paid three years earlier, the Journal reported.

Compounded drugs are rarely approved or even tested by the U.S. Food and Drug Administration because the process entails a pharmacist mixing a number of drugs to create the supposedly ideal medication for an individual's symptoms. It's considered infeasible to test each compounded mixture, and the process varies widely from state to state.

Favre, a Mississippi native who could be voted into the Pro Football Hall of Fame Saturday, has spent almost three years as the commercial representative of RX Pro. Favre was so impressed with this product that he invested in World Health Industries Inc., he told Sirius XM Radio in 2013.

“I can speak volumes on pain and narcotics use,” the Milwaukee Journal Sentinel quoted Favre as saying. He contended RX Pro “is a safe way to treat some of your ailments. It even works with cramps, stomach pain ... It’s just endless what will happen with this product and this company.”