SIOUX CITY, Iowa (AP) — A former official at a large grain warehouse in Iowa was sentenced recently to three months in prison for his role in a scheme to blend lower value oats into soybeans and then sell the mixture as soybeans to unsuspecting buyers.

Calvin Diehl, 60, of Aberdeen, South Dakota, was also fined $7,500. He pleaded guilty in June to one count of conspiracy to defraud the United States, the U.S. attorney’s office said in a news release.

Diehl was the assistant general manager at the Sioux Center grain cooperative.

Prosecutors said individuals involved in the conspiracy also made false statements and executed false certificates to federal grain inspectors. They layered soybeans on top of oats in both storage bins and trucks to deceive inspectors and customers about the quality and quantity of the grain. They also made false entries and adjustments in reports provided to the company’s bank.

After learning of the conspiracy, the Agriculture Department searched grain bins at warehouse sites in Iowa and South Dakota. It found that of the 87,996 bushels of grain at these locations, the bins actually contained only 34,354 bushels of soybeans, even though all had been certified as soybeans.