The U.S. Labor Department has ordered Gatten Sushi and sister company GTN, both of Cerritos, to pay nearly 400 workers more than $620,000 in back wages and damages.

The Los Angeles Times reported Monday that a federal investigation had revealed bosses shaved hours off workers’ timecards and docked their pay routinely for 10-minute breaks. Some sushi chefs reported having worked more than 90 hours per week without overtime.