Mexico's Interior Department has filed a complaint with federal prosecutors to investigate whether there were illegal games at a casino where an arson by drug traffickers killed 52 people.
The department says the Casino Royale in the northern city of Monterrey had permits to operate, but the agency suspects the casino was running games it wasn't allowed, including roulette and card games with money prizes.
The agency's statement Thursday says that permissible games include sports betting and bingo.
Gunmen entered the casino Aug. 25, spread gasoline and set the building on fire, trapping and asphyxiating dozens of gamblers and employees. Most of the victims were women playing bingo and slots or lunching.