A Tennessee company that provides cleaning services for animal slaughterhouses has employed people as young as 13 years old to clean dangerous equipment on overnight shifts in violation of federal law, Reuters reported, citing a court document filed on Wednesday.

The filing by the US Department of Labor accused Fayette Janitorial Service LLC of Memphis of employing 15 underaged workers to clean a Perdue Farms poultry plant in Virginia and nine at a Seaboard Triumph Foods pork-processing plant in Iowa.

The equipment cleaned by the young people included machines used to split the heads of slaughtered animals and bandsaws to cut meat. It is unlawful to hire anyone under age 18 to do such work, the Labor Department said.

“The employment of children in hazardous occupations is an egregious violation of the Fair Labor Standards Act that should never occur,” US Solicitor of Labor Seema Nanda said in a release. “The Department of Labor continues to use every available legal resource to protect workers and end child labor violations."

Neither of the company's owners, Dale Burns and Michelle Burns, nor their representatives responded to a request for comment. Representatives for Seaboard Triumph and Perdue Farms did not immediately return phone calls.

The Labor Department asked the US District Court for the Northern District of Iowa to impose a temporary restraining order on Fayette Janitorial to stop the company from using "oppressive child labor."

"This is a first step," said Scott Allen, spokesperson for the Department of Labor, adding that an investigation was still underway.

Fayette Janitorial employs 600 people in 30 states, according to its website.