Horsemeat scandal: David Cameron says offenders will feel full force of law David Cameron has promised that anyone involved in passing off horsemeat as beef will face the full force of the law after two British plants were raided and shut down. The prime minister defended the government's response to the growing scandal, saying ministers were insisting on "meaningful" tests of products by retailers and suppliers. "If there has been criminal activity there, should be the full intervention of the law," he said. The Food Standards Agency (FSA) has vowed that the investigation into the horsemeat scandal will be "relentless," and promised the agency will get to the bottom of the matter. The FSA's director of operations, Andrew Rhodes, said investigations would continue until there was "nothing left to find." Pressure on the FSA is mounting after police, acting jointly with food standards officials, raided two British meat companies on Tuesday in their first action over the food fraud. The environment secretary, Owen Paterson, was travelling to Brussels on Wednesday for an emergency meeting of European countries caught up in the scandal. Officers entered Peter Boddy Licensed Slaughterhouse in Todmorden, West Yorkshire, and Farmbox Meats, near Aberystwyth, in north Wales, as they investigated the circumstances in which horsemeat was sold as beef "for kebabs and burgers." "What we have been doing at the FSA is investigating a really broad range of different things, and we have actually exonerated quite a lot of businesses so far in our investigations, and I am sure that will continue to be the case," he said during a BBC Breakfast interview. What we are doing is focusing on the areas we think are the highest risk, so we have identified documentary evidence that has led us to take the action that we have. He added that the FSA had seized all meat at the sites as well as paperwork, and was working with police in Dyfed Powys and West Yorkshire. The slaughterhouse owner, Peter Boddy, said he would co-operate with FSA officers, and claimed they had not "raided" his Todmorden premises. He told ITV: "It was not a raid. They are welcome to visit whenever they want. They just wanted to see my records, which I will be showing them. Dafydd Raw Rees, of Farmbox Meats, told the BBC the firm was licensed to deal with horses and it had been cutting horsemeat - from the Irish Republic - for the last three weeks. As far as I am concerned, I know nothing about the plant in West Yorkshire. I have never knowingly processed horsemeat until three weeks ago," he said. There is nothing we have done here which is not totally permissible. The FSA has ordered food businesses to carry out tests on all processed beef products, first results from which are expected on Friday, although full results could take much longer. Rhodes said: "We're progressing very well through our investigations, but they are not complete yet, so I'm not going to speculate on what else we might find. But of course we don't really expect to find anything, because if people are behaving according to the law and doing what they should be doing, then there should be nothing to find. On BBC Radio 4's Today programme, Rhodes denied claims that a previous surveillance programme had been effectively stopped after pressure from the supermarkets. In Brussels, he will discuss the growing, Europe-wide crisis with the health and consumer commissioner, Tonio Borg, and his opposite numbers from France, Ireland and Romania. Cameron told the Commons it was "appalling" and "completely unacceptable" that consumers were buying beef products that turned out to contain horsemeat. He said many of the current issues had come to light thanks to tougher tests that had been ordered by ministers, and pledged that results would be made public in future. "We have also asked for meaningful tests from retailers and producers, and they will be published in full," he added. The scandal spread on Tuesday when the upmarket retailer Waitrose withdrew its Essential British Frozen Beef Meatballs after pork was detected in two batches. The plant, whose closure was announced last year, was not implicated in earlier horse or pork contamination scares at the Irish food group's Silvercrest and Dalepak sites, in County Monaghan, Ireland, and North Yorkshire. Waitrose said in a statement: "Several tests have been done on this product and, even though the results have been contradictory, we have taken the precautionary action of removing the frozen meatballs from sale and putting up customer information notices in all our branches. It added: "Although the meatballs are safe to eat, ... pork is not listed as an ingredient and should not be part of the recipe." The affected batches of the product in question, frozen Essential Waitrose 16 British Beef Meatballs (480g), have best-before-end dates of June 2013 and August 2013. Several supermarkets have been forced to withdraw burgers and readymade lasagne and bolognese products, but Tuesday's raids were the first to involve kebab meat.