The massive freighter left a port on the coast of Turkey in April, bound for the United States with a cargo of grain for farmers to feed to organic livestock.

From a desk at his farm in rural Wisconsin, John Bobbe was suspicious.

He wasn’t convinced that the cargo of the M.V. Andalucia, en route from the Black Sea to North Carolina, was legitimate. The ship’s itinerary, the owner of the grain, and the fact that the European Union had stopped recognizing the grain’s likely organic certifier stoked his doubts. He fired an e-mail to the U.S. Department of Agriculture, as he has done often over the past four years trying to turn back a rising tide of counterfeit imported organic grain.

“This thing gets more bizarre as you go along,” Bobbe said. “The problem is that consumers are being potentially defrauded, and the price for farmers is going down.”