The Charlotte Observer reported Tuesday that Columbia Farms argued in court motions that the government didn't give the company's lawyers a chance to interview workers arrested in last October's raid.
The paper said it is unclear what information the workers would have provided the defense, but defense attorneys said they wouldn't have been deported if they could have helped the government's case.
More than 330 people were arrested in the massive raid on the Greenville processing plant.
Prosecutors say most of the workers have been deported. Several dozen others pleaded guilty and are serving prison time for using illegal documents and false Social Security numbers or for re-entering the country illegally.
The plant manager, Barry Cronic, was indicted this year. Prosecutors said Mr. Cronic began hiring illegal immigrants at the Columbia Farms plant in 2000 and kept hiring them until the raid last October.
Personnel manager Elaine Crump was charged with lying on employment forms.
Both have pleaded not guilty.
Columbia Farms' parent company, House of Raeford, processes chickens and turkeys in eight plants in Georgia, the Carolinas, Louisiana and Michigan. Prosecutors have said the North Carolina-based company is cooperating and has not been charged.