Brakes, the supplier for the House of Commons Catering Service, said horsemeat had been found in a lasagne manufactured by its subsidiary division Creative Foods.
It said it had also "segregated" a frozen burger as a precaution, in addition to withdrawing a minced beef skewer that was found to contain horsemeat:
Our tests confirmed one positive equine DNA finding at between 1% and 10% on a Brakes spicy minced beef skewer and one positive test reported by a customer of our subsidiary division Creative Foods on a lasagne manufactured exclusively for them.
Brakes have also segregated a frozen burger as a precaution after equine DNA at 1% was reported to the Food Standards Agency.
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The incident took place in the city of Aurora, Illinois.
Remaining mild but not quite as warm as recently.