A New Jersey company violated labor laws by not paying staff for the full hours they worked, the DOL said.
The firm also failed to keep accurate records of staff hours and wages, the DOL said in a lawsuit.
A federal court ordered the company and its co-managers to pay staff $712,000 in back wages and damages.
Employees regularly worked between 45 and 54 hours a week, but the company didn't pay staff extra for overtime, the DOL said.
The company paid staff in cash for overtime hours and told them not to clock out "to conceal the fact that employees worked more than forty hours a week," per the lawsuit.