Authorities were investigating a new suspected case of crop contamination on Thursday – the second in the Pacific north-west in five months – after samples of hay tested positive for genetically modified traits.
The investigation was ordered after a farmer in Washington state reported that his alfalfa shipments had been rejected for export after testing positive for genetic modification. Results were expected as early as Friday.
If confirmed, it would be the second known case of GM contamination in a major American crop since May, when university scientists confirmed the presence of a banned GM wheat growing in a farmer's field in Oregon.
The suspected outbreak comes in the run-up to a ballot measure in Washington state that would require mandatory labelling of all GM foods.