BOISE, Idaho (AP) — Farmers in Idaho have filed a potentially class action lawsuit against seed giant Monsanto after genetically engineered wheat was found in an eastern Oregon field.

The farmers, represented by a Boise law firm, filed the federal lawsuit Friday contending that Monsanto's development of Roundup Ready wheat resulted in increased production costs and lowered prices because the genetically engineered wheat is likely to infiltrate the non-genetically engineered wheat supply.

No genetically engineered wheat has been approved for U.S. farming, and the discovery of the Roundup Ready wheat growing in Oregon in May prompted Japan to suspend some wheat imports.

Monsanto didn't immediately respond to a request for comment, but the company has said a similar lawsuit filed in Kansas was done so prematurely and without any evidence of fault, and that it plans to present a vigorous defense.

Already a handful of lawsuits have been filed in other courts around the country over the same issue. The lawsuit in Boise's U.S. District Court was filed Friday by Behrend, Behrend & Knittel Farms and CoMa Farms, both in Aberdeen, and County Line Farms in American Falls. The Idaho farmers are asking for class-action status on behalf of thousands farmers of soft white wheat in Idaho, Oregon, Washington and other states.

Monsanto began in 1997 to develop a strain of wheat that is resistant to the company's popular pesticide, Roundup. The result, dubbed Roundup Ready wheat, was field tested in 16 states between 1998 and 2005, including fields owned by CoMa Farms in Aberdeen, according to the lawsuit. At the time Monsanto had applied to USDA for permission to develop the engineered wheat, but the company later pulled its application.

The farmers contend that Monsanto failed to take steps to make sure the genetically engineered plants didn't contaminate regular wheat through cross-pollination, mixing of seeds or other means. Because the wheat industry uses a system that gathers and commingles wheat from thousands of farms for sales and shipping, the farmers contend Monsanto should have known that it would be virtually impossible to prevent the Roundup Ready wheat from infiltrating the non-genetically engineered wheat supply.

"Monsanto knew, or should have known, that the existence of genetically-engineered wheat — commingled with the general wheat supply — would cause significant disruptions in the wheat export market, and that such a situation could involve huge disruptions in the wheat trade while imposing additional costs on U.S. wheat farmers and specifically Pacific Northwest soft white wheat farmers. These costs eventually would detrimentally impact worldwide prices for Pacific Northwest soft white wheat, causing significant financial damage to wheat farmers," attorney Benjamin Schwartzman wrote in the lawsuit.

The farmers say the discovery of the genetically engineered wheat growing in Oregon has diminished prices for all soft white wheat because of the loss of export and domestic markets, and that it has also increased costs for growers who must go through extensive testing to prove the wheat from their fields isn't contaminated with genetically engineered wheat before they can sell to some buyers.

They are asking for compensatory and punitive damages in an amount to be determined at trial, and they want a judge to order Monsanto to decontaminate the farmland and transportation and harvesting equipment of all affected farmers.