New price fixing claims have been brought against US meat giants including Tyson Foods and Pilgrim’s Pride .

News agency Bloomberg is reporting that supermarket and restaurant chains, including Suoervalu, Publix Suoer Markets, Associated Grocers of the South and Meijer , sued the companies in federal court in Chicago on Tuesday (3 July). The complaint cites chicken purchases from 2008 to 2016.

Similar claims have already been made (on 29 June) in the Chicago courts by retail heavyweights Kroger, Albertsons and Hy-Vee.

Bloomberg quotes a Tyson spokesman saying: “The lawsuits are unfounded, and we are determined to defend against these baseless claims.”

US meat companies, including Tyson Foods and Hormel Foods , were hit last week with a lawsuit accusing them of conspiring to inflate pork prices in an effort to boost profit at consumers’ expense.

Nine defendants have been accused of colluding since 2009 to limit production, with the “intent and expected result” of increasing pork prices.

The litigants claim defendant Agri Stats began giving pork companies “benchmarking” reports, which typically allow comparisons of profits and performance but also offered “sensitive” data on costs, prices and slaughter rates and the ability to decipher which data belonged to which companies and as a result control supply and price.

“The provision of this detailed information acts as the proverbial smoke-filled room of the cartels of yesteryear,” the complaint said.

That case – Duryea et al v. Agri Stats Inc et al – is likely to be vigorously defended by the food groups, which also include the US unit of Brazil’s JBS and WH Group’s Smithfield Foods.