A sudden clampdown on a British abattoir product that previously filled cut-price burgers and pies may be largely responsible for the horse meat scandal, it was claimed today.
Suppliers were forced to seek cheap alternatives abroad when European regulators refused to recognise the product, known as de-sinewed meat or DSM.
The ruling came as a bombshell because it meant beef products containing DSM could no longer be sold.
Just two days notice was given before the change occurred in April last year.
Expensive "real" meat from British sources - in the form of fine mince - was not an option because of pressure from retailers to keep prices down, according to a leading food consultant and former member of the Food Standards Authority.
The only alternative was to seek out new sources of continental meat that were cheap enough to satisfy the supermarkets.
Dr Mark Woolfe, who was in charge of food authenticity at the FSA until 2009, said: "It was very, very badly done, I thought.
"I think there was an obvious risk. If you take a large chunk of raw material out of the market people have got to find alternative supplies.
"In principle there shouldn't be anything wrong with going to Europe because the same laws cover the whole of the EU. But in practice the longer and more complex the food chain, the more difficult it is to control. I think that's something we've learned the hard way quite recently."
Speaking at a news briefing in London, Dr Woolfe said he thought the EC ruling was a major factor behind the appearance of horsemeat in beef products.
Prior to the decision, thousands of tonnes of DSM had been used by the UK meat processing industry each year, he added.
He suggested that lamb products might also be at risk of contamination since many of them had also previously contained the material.
DSM was introduced in around 2000 as a cheap and plentiful filler for meat products.
It is produced by scraping meat residue off carcasses and then removing the sinews and bone fragments.
But European Commission inspectors ruled that to comply with EU law, DSM had to be reclassified as mechanically separated meat (MSM).
This is an even more basic product made by forcing residues through a sieve under pressure. The result is a material that resembles pink toothpaste.
Under British labelling regulations, MSM cannot be described as beef, lamb or any other kind of meat. Products made with the material must clearly be labelled as containing MSM. In addition, there are rules about minimum level of meat content in meat products.
As a result it was no longer possible to sell products largely composed of de-sinewed meat.
Dr Woolfe criticised supermarket chains for putting pressure on suppliers and not questioning the source of the cheap ingredients replacing DSM.
"Retailers seemed to be very unconcerned about this change at the time from what I can gather," he said.
"I think they should have questioned, if these materials were not going to be used, what (new) raw materials are going to be used. Maybe they should have been a little bit more vigilant."
He added: "Lets face it, on value products they squeeze the suppliers. They give them very low margins.
"They weren't prepared to give more money when this thing occurred so they forced suppliers to look for alternative supplies of meat to DSM."
Dr Woolfe believed pressure from supermarket chiefs also helped to kill off an FSA surveillance committee which gathered intelligence on rogue suppliers.
"I don't think the higher management of the retailers particularly liked our name and shame policy - they felt it was food enforcement by the back door," he said.
After 2005 the agency wound down its surveillance operations which were taken over by local authorities.
An FSA spokesman said: "The problem here is either gross negligence or criminal activity, potentially across Europe. We're not aware of any evidence to suggest that the reclassification of DSM as Mechanically Separated Meat (MSM) in the UK has lead to the contamination of beef products with horsemeat.
"Regardless of financial pressures that may have arisen from the DSM moratorium, the food industry is required to ensure their products are legally produced, safe to eat and are what they say on the label. There is simply no excuse for substituting beef for horsemeat."