Government ministers were warned in 2011 that horse meat was illegally entering the human food chain, it has been claimed.
John Young, a former manager at the Meat Hygiene Service, now part of the Food Standards Agency (FSA), told the Sunday Times he helped draft a letter to the Department for Environment, Food and Rural Affairs (Defra) in April that year.
But he told the paper the letter to former minister Sir Jim Paice on behalf of Britain's largest horse meat exporter, High Peak Meat Exports, which warned that flesh with possible drug residue getting into food could blow up into a scandal, was ignored.
In the letter the company warned the Government that its passport scheme designed to stop meat containing the anti-inflammatory drug phenylbutazone, known as bute, getting into the food chain was not working, calling it a "debacle". "Defra gave nearly 80 organisations the authority to produce passports and some of them are little better than children could produce... It's a complete mess," he said.
Sir Jim said he did not remember seeing the warnings, telling the Sunday Times: "If this information was in Defra and was not being acted upon, it warrants further investigation. I would like to know why on earth I was not being told about it." He admitted the horse passport scheme to stop bute getting into the food chain was not working, saying: "We now know that and we need to know why."
Meanwhile the boss of one of the country's leading supermarkets warned on Sunday that consumers could end up paying the price for the horse meat scandal, as ensuring food has the best safety guarantees means it can no longer be regarded as a "cheap commodity".
Writing in the Sunday Telegraph, Mark Price, the managing director of Waitrose, said rising costs of rearing animals could mean that "somewhere along that long supply route, somebody has looked to cheat and take advantage of these circumstances either for their own personal greed or to keep a company afloat". Waitrose has not been affected by the scandal, which Mr Price puts down to its rigorous verification processes.
But he said that not every part of the food industry has been so diligent. "If meat is being purchased blind from outside the UK, and sometimes even via the internet in bulk, it is less easy to find those guarantees that full knowledge and traceability give," he told the newspaper. "The simple fact is that food cannot be seen as a cheap commodity when so many factors are working against that premise, including population growth, climate change, greater urbanisation, and the spread of Westernised diet in the developing world."
Three men arrested by police investigating the horse meat scandal were released on bail on Saturday as officials continued to examine evidence on Sunday from three plants raided on Friday. The FSA said it had passed on evidence from two premises in Tottenham, north London, and one in Hull, East Yorkshire, to Europol - the European Union's law enforcement agency - after investigators, accompanied by police officers and local authority officials, removed meat samples for testing.
The move comes after Dafydd Raw-Rees, 64, the owner of Farmbox Meats near Aberystwyth, and a 42-year-old man, were arrested in Wales on Thursday on suspicion of offences under the Fraud Act.