We'll never know how many ate horse
Police outside a meat processing plant in Todmorden, West Yorkshire, that was raided as part of the inquiry into the horse meat scandal
It is unlikely the exact number of people in the UK who have unwittingly eaten horse meat will ever be known, the chief executive of the Food Standards Agency (FSA) has conceded.
Catherine Brown said that testing was the right way to address the issue, and said the focus would be on areas of higher risk.
But she admitted that how many people who had unknowingly eaten horse meat was likely to be impossible to ascertain.
"I don't think that we ever will (know how many), because these tests are a snapshot, so even where we find things it is very hard to work out how long, what number of batches, so I think it is unlikely that we will ever know that. It is shocking," she told the BBC.
Her comments came as the head of a major UK supermarket chain insisted that the horse meat scandal was not "the tip of an iceberg".
Justin King, chief executive of Sainsbury's told BBC's Newsnight programme that supermarkets had not been slow to react to the scandal, but conceded there was a long way to go before the food industry could fully explain how the crisis has come about.
He said: "I don't think it's the tip of an iceberg. I think there are some encouraging signs from today's tests that we are starting to get to the bottom of this particular issue.
"We, in Sainsbury's, have a huge testing programme - we have 50-odd people, whose full-time jobs are to test product.
"They test raw materials when they come into the factory. The product is delivered to our warehouses and we buy product, as customers do, to test it too. And most of the industry would say something similar. So, we go to great lengths to ensure our food is what we expect it to be. Trust is the core of our businesses."
Officials investigating the horse meat mis-labelling scandal will continue examining evidence after three more plants were raided. The FSA visited two premises in Tottenham, London and one in Hull, Yorkshire, on Thursday.