The U.S. Department of Justice is being sued over its refusal to publicly disclose a $2 million non-prosecution agreement prosecutors reached with a Houston-based tree services company that employed undocumented workers.

The U.S. Attorney’s Office of the Southern District of Texas issued a news release in May 2012 revealing the deal between prosecutors and ABC Professional Tree Services Inc. The company agreed to forfeit $2 million in revenue that flowed from the use of undocumented workers between 2006 and 2011, DOJ officials said.