Japan suspended certain wheat imports from the United States on Thursday after a genetically modified crop was found growing in an eastern Oregon field.
The strain of wheat was engineered by seed developer Monsanto to be resistant to herbicides.
The United States Department of Agriculture, Monsanto and the farmer are all saying they don't know how the wheat got there.
The European Union is also urging its members to test certain wheat shipments from the United States.
So far, none of the wheat has been found in Idaho.
The Idaho Wheat Commission and State Department of Agriculture said the grain would still be safe even with the Monsanto gene.
But they are concerned with the effect on Idaho wheat sales because Northwest wheat farmers market together.