Cottage pie that was delivered to 47 schools in Lancashire has tested positive for horse DNA.
The product has now been withdrawn from kitchens.
Officials at Lancashire County Council say the amount of horse consumed by the children will have been 'minute.'
Analysts at one of six laboratories in the country doing the FSA's tests discovered the contaminated product late yesterday.
Scientists uncovered equine DNA at 0.1% concentration in samples.
Headteachers have been alerted.
More top news
Remaining largely cloudy with patchy drizzle over hills. Becoming milder, breezy with some brighter breaks in the west on Friday
Saturday looks like the best day of the weekend. Mainly dry for both Saturday and Sunday but a cooler, cloudier finish
Another largely cloudy and murky day. Perhaps a little brighter and feeling milder for Friday