Grocery storeA federal lawsuit has been filed by several major U.S. supermarket chains including Hy-Vee, Kroger, Save Mart and US Foods. The supermarkets say several pork processors are conspiring to fix pork prices, dating back to at least 2009. Filed on Dec. 28, the suit accuses the defendants of working with Indiana Packers Corp. to “fix, raise, maintain and stabilize the price of pork” in U.S. markets, which is in violation of the Sherman Act of 1890.

Most of the listed defendants, including Tyson, JBS and other processing giants also face accusations in a similar lawsuit filed by restaurant chains such as Buffalo Wild Wings, Sonic and Jimmy John’s.

Read more on the federal lawsuit here.