IT is now clear that, in the labyrinthine process of taking so many meat products from abattoir to supermarket shelf, traceability has been lost and, all too probably, the door has been opened to fraud.

This is a scandal. As of yesterday, companies in the UK, including Freshlink in Glasgow, which supplied meatballs containing pork to Waitrose, a slaughterhouse in Yorkshire and a meat supplier which handles horsemeat in Wales, had come under investigation by the Food Standards Agency (FSA). There could be no guarantee that British produce was immune.

The FSA has promised its inquiries will be relentless but there must be an equally thorough investigation into how this outrageous false representation of food became possible.

Tightening regulations in Britain, however, will not be sufficient. The sheer scale of the problem – with horsemeat being found in "beef" products in Britain, Ireland, Spain, Sweden and Holland and the French firm which produced burgers for Findus supplying 16 countries – shows that traceability and compliance are required across the EU.

Ministers in all parts of the UK with responsibilities for agriculture, food safety and health must ask whether restrictions on mechanically-recovered meat in the UK in the wake of the BSE crisis in the 1990s that did not apply elsewhere were a factor in creating the loopholes that have been exposed by the horsemeat scandal.

It was the spectre of meat infected by BSE causing a fatal brain disease in humans that led to the Food Standards Agency being set up as an independent body to ensure compliance with regulation.That was designed to bolster public confidence but horsemeat masquerading as beef has lost public trust. Much is now made of the traceability of fresh food in this country and shoppers increasingly want to know where produce comes from. That is more difficult with processed food which is likely to contain ingredients from more than one country but there must be absolute transparency as to the contents and the origin of the main constituent. It is essential that people who buy beef in good faith do not end up with horse or pork on their plates.

An assurance that there is no health risk is not good enough when potential fraud raises the possibility that the horses involved may have received medication that could be harmful to humans. It is now obvious that the meat trade must be rigorously policed at every step of an often long and complex process.

The EU developed a food safety regime that emphasised traceability but the lack of integrity now demonstrated in the supply chain raises questions about its ability to police an industry involving multiple processors across national borders. Whether the contaminated and falsely-labelled food is eventually found to be the result of negligence or criminal activity, those involved must be prosecuted. In particular, the international food conglomerates engaged in price wars must shoulder their share of responsibility.

Everyone must have confidence in the integrity of their food, whatever their budget. This is the moment for the FSA to prove its worth.