Two 10-year-old children were found working at a Louisville McDonald’s restaurant — sometimes until 2 a.m. — the US Department of Labor said Tuesday.

The revelation was part of an investigation into the child labor law violations in the Southeast. The agency also found three franchisees that own more than 60 McDonald’s locations in Kentucky, Indiana, Maryland and Ohio, “employed 305 children to work more than the legally permitted hours and perform tasks prohibited by law for young workers,” the Labor Department said in a statement.

“Investigators from the department’s Wage and Hour Division found two 10-year-old workers at a Louisville McDonald’s restaurant among many violations of federal labor laws committed by three Kentucky McDonald’s franchise operators,” the release said. “Investigators also determined two 10-year-old children were employed – but not paid – and sometimes worked as late as 2 a.m.”

Tiffanie Boyd, senior vice president and chief people officer at McDonald’s USA, told CNN: “These reports are unacceptable, deeply troubling and run afoul of the high expectations we have for the entire McDonald’s brand. […] We are committed to ensuring our franchisees have the resources they need to foster safe workplaces for all employees and maintain compliance with all labor laws.”

Franchisee Bauer Foods LLC confirmed to CNN that the two 10-year-olds allegedly employed were children of a night manager who were visiting their parent at work and were not approved by franchisee organization management to be in that part of the restaurant.

Two of the other franchisees, Archways Richwood and Bell Restaurant Group, did not immediately respond to a request for comment.

The three franchisees face a combined $212,754 in civil money penalties for the child labor violations, the release said.

“Too often, employers fail to follow the child labor laws that protect young workers,” said Karen Garnett-Civils, the agency’s wage and hour division district director, in a statement. “Under no circumstances should there ever be a 10-year-old child working in a fast-food kitchen around hot grills, ovens and deep fryers.” (CNN)

•PHOTO:Three McDonald's franchisees that own more than 60 McDonald's locations in Kentucky, Indiana, Maryland and Ohio employed 305 children to work more than the legally permitted hours, the DOL found. Tayfun Coskun/Anadolu Agency via Getty Images