An investigation by the Food Safety Authority of Ireland into a variety of supermarket meat products found traces of horse DNA in 37% of them, but most damningly concluded that the Tesco value burgers it tested contained more than just a trace of horse – the proportion was actually 29% of their meat content.
FSA Ireland also found that pig DNA was present in many of the meat products tested. While less of an issue with the general public than the horsemeat, this raised serious issues for consumers with religious objections to pigmeat.
The offending burgers have since been traced to two Irish processing plants – Liffey Meats and Silvercrest Food – and Yorkshire's Dalepak Hambleton plant, from where they were sold into Tesco, Dunnes, Lidl, Aldi and Iceland stores in the UK and Ireland.
Midweek, Tesco rushed all its beef burger products off its shelves – whether affected or not – while the FSA stressed that the horsemeat was not a threat to food safety, just a breach of ingredient labelling rules.
However the damage had already been done, with the retail chain seeing £300m drop off its share value within hours of the news, while internet social networks – now of vast importance to public opinion – lit up with a mixture of outcry and jokes cementing the story in shoppers' minds.
As The Scottish Farmer went to press, what remained to be seen was whether Tesco's troubles would make the public pay more attention to the provenance of meat products – or just put them off altogether.
Quality Meat Scotland chairman, Jim McLaren, highlighted the traceability of the Scotch Beef brand: "Our industry is absolutely committed to protecting the integrity of our Scotch Beef brand and we take great pride in the world-leading traceability we have in place.
"The quality assurance schemes in Scotland guarantee Scotch Beef comes from cattle born, reared and slaughtered in Scotland."
NFU Scotland condemned the FSA findings, saying that they tarnished the reputation of the UK food industry and the many farmers who provided traceable Scotch Beef to the market.
The union's communications director, Bob Carruth, said: "This is a spectacular own goal for parts of our food sector and doesn't reflect on the fantastic job being done by Scottish beef farmers in providing the market with fresh, tasty, traceable, assured beef.
"Scottish farmers will continue to supply the food chain in the firm and justifiable belief that all meat that goes into a beef burger should be beef. Consumers expect no less."
Speaking from Farmers For Action, UK and Northern Ireland co-ordinator William Taylor blamed supermarket price wars for driving processors to 'devious lengths' to supply large orders and still make a profit.
"FSA must again be inspecting abattoirs' finished products at random, unannounced and monthly at the very least," he suggested.
One of the processing plants involved has blamed European meat for the problem.
Silvercrest, which is a subsidiary of ABP Foods, said: "Silvercrest has never purchased or traded in equine product and has launched a full-scale investigation into two continental European third party suppliers who are the suspected source of the product in question."
Tesco's group technical director Tim Smith– who may be particularly embarrassed as a former UK FSA chief – said that the company would not be taking products from the processing companies involved until the issue was resolved.