The U.S. Department of Labor has opened an investigation against Hearthside Food Solutions, one of the largest U.S. food contractors that makes and packages products for well-known snack and cereal brands, for reportedly employing underage workers at its factories and violating child labor laws.

This is according to two sources with knowledge of the matter.

The company has come under scrutiny after a New York Times investigation showed Hearthside's factories employed underage workers making Chewy granola bars and bags of Lucky Charms and Cheetos, which the company would later ship around the country.