The U.S. Justice Department's investigation into alleged anticompetitive practices by Dairy Farmers of America Inc. has broadened. The Justice Department has hired Yale University to study DFA's Southeast network of dairy plants, milk bottlers and marketing agencies, according to a recent article fromAssociated Press.

Since the probe was made public at an August 5 meeting in Louisiana, investigators have expanded their investigation to include more than a dozen states. The Yale investigators are looking into how the cooperative could be split up, according to farmers who are fighting the expansion of DFA.

Justice Department officials declined to comment on the ongoing investigation or on whether it has commissioned a study. DFA officials said they were unaware of a study being undertaken.

DFA spokeswoman Agnes Schafer, said the Kansas City, Mo.-based co-op believes the Justice Department "will find that our relationships are consistent with the law." Federal investigators are sending out questionnaires to other cooperatives and milk marketing agencies across the country to better understand how the industry works and DFA's role within it, according to an AP source.