Not long after genetically-altered wheat was discovered in an eastern Oregon field, two Washington state farmers have followed the lead of a Kansas grower and are suing Monsanto.

Thursday, Washington wheat growers Dreger Enterprizes of Creston and Wahl Ranch of Lind sued Monsanto. They claim the discovery of the wheat has hurt farmers export markets. The suit was filed in U.S. District Court in Spokane, was done on behalf of all U.S. domestic soft white wheat growers, and seeks class-action status.

According to Oregon State University researchers and the Oregon State Department of Agriculture, earlier this spring a farmer found strains of a genetically-altered wheat growing on his farm. The wheat was not approved for commercial use and was never released. Farmers are not allowed to grow such wheat in the U.S. due to trade agreements with other countries. Concerns over genetically-modified wheat has kept it off the open market.

It is still not known how the wheat got there, or if it's from the Monsanto crop.