New DNA tests at the Yorkshire site involved in the burger contamination scandal have come back negative for horse and pig DNA, the Food Standards Agency has announced.

North Yorkshire Trading Standards conducted tests on the specific burger lines that were named in a survey by the Food Safety Authority of Ireland, which was carried out in late 2012 and published earlier in January. “They took seven samples, comprising all the meat being used currently in the production of these lines,” the FSA said. “Neither horse nor pork DNA was detected in any of these samples.”

The FSA added investigations continued into how horse and pig DNA came to be in those burgers tested by the FSAI in 2012.

Waitrose said today it had removed own-label frozen burger lines produced by Dalepak as a precautionary measure.

The British Retail Consortium said it temporarily suspended Dalepak’s BRC certification on 18 January but had since reinstated it after the site passed an audit.