Middleweight Julio Cesar Chavez Jr., the son of the former three-division champion and Mexican icon, tested positive for a banned substance in conjunction with his Nov. 14 fight against Troy Rowland, according to the Nevada State Athletic Commission.
Executive director Keith Kizer said Saturday that Chavez, who tested positive for Furosemide, a diuretic, faces a fine and suspension.
Chavez (41-0-1, 30 KOs) won a 10-round decision against Rowland in the co-featured bout on the Manny Pacquiao-Miguel Cotto undercard at the MGM Grand in Las Vegas. Kizer said the positive results came from Chavez's pre-fight urinalysis.
All of the other boxers on the card had negative test results, Kizer said.
The commission filed a formal complaint on Tuesday against Chavez. He has 20 days to respond, which will be followed by a hearing at a date to be determined. If Chavez does not respond to the complaint, the commission may reach a decision in his absence.
If the commission upholds the test result, which it usually does, the result of the fight would be changed to a no decision.
According to the complaint, Chavez, 23, faces a suspension of up to nine months and a fine that could equal his entire $100,000 purse, although fighters are typically fined a smaller portion in these cases. In addition, Chavez would be required to provide a negative urine test before he's allowed to fight in Nevada again.
Chavez, a cash cow for promoters Top Rank and Mexico-based Zanfer Promotions, would be barred from fighting in the United States during a suspension. However, it would not prevent him from fighting in Mexico, where he has fought most of his bouts and draws big crowds as the headliner on Top Rank's series of "Latin Fury" pay-per-view cards.
"I think it was an innocent mistake, one that the Nevada commission will have to deal with, as well as Chavez," said Top Rank's Carl Moretti. "I don't think he knew diuretics were banned by the Nevada commission."
Dan Rafael covers boxing for ESPN.com.