(CNN) -- Two Colorado cantaloupe farmers could soon plead guilty to federal charges in the case of a 2011 listeria outbreak that resulted in 33 deaths and many more illnesses.
Eric and Ryan Jensen, of Holly, who are accused of introducing adulterated food into the food supply, have entered plea deals with federal prosecutors, according to documents filed in the U.S. District Court in Denver through their attorneys.
The agreements mean the Jensen brothers could plead guilty to six criminal counts in exchange for lesser charges. They previously pleaded not guilty to all charges, which each carry a fine of $250,000 and up to one year in prison.
Specifics of the plea would remain unknown until announced at a public hearing, the date of which is still being decided by a judge. Ryan Jensen's attorney, Richard Banta, said they reached an agreement with prosecutors "in principle," but declined to elaborate.
Eric Jensen's attorney didn't immediately return phone calls seeking comment.
The outbreak in September 2011 triggered a miscarriage in one woman and sickened more than 115 others. It was the deadliest outbreak of food borne illness in more than a quarter-century, said the Centers for Disease Control and Prevention.
The U.S. Food and Drug Administration also cited the farm's "serious design flaws" and a "lack of awareness" of safety standards as possible sources of the bacterial contamination.
Also at issue were accusations the company that inspected the Jensen brothers' farm ignored federal regulators' "best and most timely" advice on processing produce, as a congressional report found.