Washington State ag officials are testing alfalfa samples after a farmer reported his crop tested positive for a genetically modified trait that should not have been there, according to a spokesman for the state.

The farmer’s hay was rejected for export in late August, says Mike Louisell, public information officer with the Washington State Department of Agriculture (WSDA).

WSDA collected samples of the farmer’s seed and alfalfa, and expects results of the tests later today.

The state is testing his seed to see whether it was mislabeled as not containing genetically modified traits. At this time, WSDA does not believe the farmer’s field was contaminated.

“It’s not the seed he thought he was buying,” Louisell says.

Roundup Ready alfalfa, developed by Forage Genetics International for Monsanto Co., was deregulated by USDA in 2011, and many farmers have taken to the varieties that withstand treatments from Roundup herbicide.