Wolverine Packing is Red Cow's meat distributor and Double Black Diamond prepares and sells the product, according to the lawsuit. It follows outbreak in November, when at least 20 E. coli cases were reported to the Minnesota Department of Health (MDH), with people saying they consumed burgers from various Twin Cities restaurants.

The civil lawsuit alleges that Red Cow and its meat distributor, Wolverine Packing Co., were negligent in their processing and cooking of ground beef

In a statement, Red Cow said it took "immediate action" and changed distributors after learning about the infections.

Three people who were sickened in an E. coli outbreak at Red Cow locations in November have sued the Twin Cities restaurant chain and the food distributor that supplied the contaminated ground beef.