DES MOINES, Iowa (AP) — A Tennessee-based sanitation company has agreed to pay more than half a million dollars after a federal investigation found it illegally hired at least two dozen children to clean dangerous meat processing facilities in Iowa and Virginia.

The U.S. Department of Labor announced Monday that Fayette Janitorial Service LLC entered into a consent judgment, in which the company agrees to nearly $650,000 in civil penalties and the court-ordered mandate that it no longer employs minors. The February filing indicated federal investigators believed at least four children had still been working at one Iowa slaughterhouse as of Dec. 12.

U.S. law prohibits companies from employing people younger than 18 to work in meat processing plants because of the hazards.

The Labor Department alleged that Fayette used 15 underage workers at a Perdue Farms plant in Accomac, Virginia, and at least nine at Seaboard Triumph Foods in Sioux City, Iowa. The work included sanitizing dangerous equipment like head splitters, jaw pullers and meat bandsaws in hazardous conditions where animals are killed and rendered.