DES MOINES, Ia. — New court filings in an Iowa courtroom show the vast scope of a grain fraud operation masterminded by a Chillicothe man.

61-year-old Randy Constant was charged last week with a single felony count of wire fraud and entered a guilty plea the same day.

Constant, along with associates not named in court records, defrauded tens of thousands of customers across the United States who believed they were purchasing certified organic grain, prosecutors said in the new documents, filed in Cedar Rapids on Thursday.

Constant falsely marketed non-organic grain as its more expensive counterpart in a $140 million fraud scheme dating back to 2010.

A plea deal was struck between prosecutors and Constant in which he would forfeit $128 million.

Constant is set to be sentenced on the federal fraud charge in early 2019. He could face up to 20 years in federal prison.