DOW JONES NEWSWIRES The Justice Department filed a lawsuit against a Smithfield Foods Inc. (SFD) unit, alleging the company imposed unnecessary documentary requirements on non-U.S. citizens when establishing their authority to work in the country. The department's investigation allegedly found that pork producer Farmfield Foods Inc. required all newly hired, non-U.S. citizens and some foreign-born U.S. citizens at an Illinois plant to present specific and, in come cases, extra work authorization documents beyond those required by federal law. Missouri-based Farmland allegedly imposed greater and different requirements on non-U.S. and foreign-born workers as compared to applicants who were native-born, the Justice Department said. The lawsuit charging Farmland with discriminatory practices has been filed before the Office of the Chief Administrative Hearing Officer within a division of the Justice Department. A Smithfield representative wasn't immediately available to comment on the litigation. Shares of Smithfield closed down 3 cents to $21.84 on Monday and were inactive after hours. -By John Kell, Dow Jones Newswires; 212-416-2480; john.kell@dowjones.com