SAN BERNARDINO, Calif. — San Bernardino County prosecutors say they are investigating labor practices at the Chino slaughterhouse involved in the largest beef recall in U.S. history, including in Hawai'i.

Assistant District Attorney Dennis Christy told The Associated Press on Tuesday that government-regulated businesses that don't play by the rules can gain an unfair advantage over their competitors — and that can result in civil penalties.

The animal cruelty investigation that's led to the arrest of two workers at the Westland/Hallmark Meat Company is also continuing. Undercover video showed workers apparently forcing so-called "downer" cattle to slaughter in violation of federal regulations.

The president of Westland/Hallmark, Steve Mendell, is set to testify to Congress under subpoena on Wednesday.