One of the largest purchasers of Pacific Northwest wheat is easing restrictions on imports of wheat from the region after repeated testing has shown no contamination in the commercial supply from experimental genetically modified wheat, which was discovered on a farm in Oregon this spring.

South Korea said it will resume purchasing soft white wheat from the Pacific Northwest. It will continue to test wheat shipments for presence of the transgenic material, but it will not restrict purchases of wheat grown in Oregon, said Blake Rowe, chief executive of the Oregon Wheat Commission.

The largest purchaser of wheat from the Pacific Northwest, Japan, remains leery of importing any Pacific Northwest wheat from the U.S. Agriculture officials are working with Japanese officials to resume sales. Rowe said the Japanese are waiting for the USDA investigation to finish and it’s the only country that has not resumed its wheat purchasing since the GM wheat was found.

Monsanto field tested a wheat variety that was engineered to resist glyphosate herbicide between 1998 and 2005. Monsanto withdrew its application for federal approval after discovering that the global market would not support sales of any GM wheat, not due to any defectiveness or threat to humans from the variety.

The GM wheat was discovered in one farmer’s field in Oregon this spring and federal investigators continue to seek answers as to how the seed survived and germinated. Other than the one field, the Roundup Ready wheat has not been found elsewhere.

South Korea’s decision to resume wheat purchases is good news for wheat industry as harvest in several Pacific Northwest states is beginning.

White wheat sales to Japan are 36 percent below the same point in 2012, according to the U.S. Wheat Associates. Sales to South Korea were 60 percent less than last year. Sales to the Philippines and China are also below sales in 2012.