The UK environment secretary has said he fears "an international criminal conspiracy" may lie behind the horsemeat crisis following an emergency meeting with leading food retailers.
As he emerged from the summit with Food Standards Agency (FSA) officials and supermarket bosses, Owen Paterson said that police may be involved in the investigation into how meat from horses had found its way into a range of processed 'beef' products.
Paterson said it had been agreed that there would be "a very rapid analysis of current products", with results by the end of next week, to understand "the extent of this problem which is either caused by gross incompetence or what I suspect is actually an international criminal conspiracy".
Sources in the horse slaughter industry have told the Observer that they believe Polish and Italian mafia gangs may be involved in a multibillion pound fraud to substitiute horse meat for beef, intimidating vets and abattoir officials into authenticating horsemeat as beef.
"If there's a criminal act we will work with the authorities wherever they are to ensure the appropriate measures are taken," Paterson said.
He branded the scandal a "fraud on the British public" and warned the scandal "could go deeper than we thought," warning that further products may be found to contain horsemeat.
Findus also announced that it would be taking legal action against a supplier after some products were found to contain 100 per cent horsemeat.
"Findus is taking legal advice about the grounds for pursuing a case against its suppliers, regarding what they believe is their suppliers' failure to meet contractual obligations about product integrity," the company said in a statement.
"The early results from Findus UK's internal investigation strongly suggest that the horsemeat contamination in Beef Lasagne was not accidental."
"Ultimate responsibility for the integrity of what is sold on their label has to lie with the retailer," said Paterson, as several of Britain's leading supermarket chains including Tesco, Aldi, Sainsburys and Asda attended the meeting today (9 February) at the Department for Environment, Food and Rural Affairs.
They agreed to share meat test results with the FSA on a quarterly basis and reimburse customers who bought contaminated products.
Customers have been advised not to consume affected products by the FSA.
British police said they had met with officials from the FSA but not yet commenced an investigation.
Findus was not invited to the meeting today, but a member of the Food and Drink Federation, of which it is a member, was present.
Earlier the company came under attack from Labour leader Ed Miliband, after reports claimed that they had known for days before withdrawing them that some of their products contained 100 percent horsemeat.
Miliband told Sky News: "The head of the company needs to come to Britain and explain himself, and who knew what when.
"Many customers were innocently buying Findus products when it appears that the company may have known it was likely to be contaminated by horsemeat."
Findus also denied it knew about the possible presence of horsemeat in their products as long ago as August last year.
The company said it ordered initial tests on their products on 22 January, the presence of horsemeat was confirmed on 29 January, and products containing traces of horse DNA were recalled on 2 February.
Aldi, which found some products containing 30 to 100 percent horsemeat this week, said that it felt "angry and let down" by its French supplier Comigel, which also sold Findus contaminated meat.
Comigel said that the meat was in turn supplied by the company Spanghero, which today announced it is going to sue a Romanian supplier.
Aldi added that it would test the meals for the veterinary drug phenylbutazone, often referred to as bute, which can cause health problems in humans and is banned from food products, but said it was confident the meals were safe.