Half of the meat samples tested by a local authority food safety team last year contained species of animals not identified on their labels.
Beefburgers and sausages sampled by Leicester Trading Standards contained undeclared chicken, while samples of lamb curry were found to contain cheaper beef or a mix of beef and lamb or turkey.
Leicester city council is the latest authority to publish results from a targeted survey of meat products on sale in its area in 2013, which shows that gross contamination of meat is widespread.
The findings follow similar results from West Yorkshire, North Yorkshire and West Sussex councils that also found consumers were regularly being misled about the contents of their food.
Minced beef samples were found in Leicester that were a mix of meat from three species; beef, chicken and lamb. Lamb mince samples contained not only lamb but also beef, chicken and turkey. Twelve out of 20 samples of doner kebab meat also failed to meet legal requirements because the species of animals used were misdescribed.
In total, 105 samples of meat products were collected from butchers, retailers, wholesalers, manufacturers, fast food shops and caterers in Leicester and tested by the public analyst. Of these, 50 samples failed to meet legal requirements for composition and labelling, 47 of them because they contained undeclared species of animal.
Leicester council says deliberate deception is likely to be the cause in several cases, while in others failure to clean machines properly between processing batches of different meats may be the explanation.
In 18 samples, meat of an undeclared species was a major ingredient, accounting for levels of between 60% and 100%. The rest of the failed samples tested positive for the presence of at least one type of undeclared meat at medium (30-60%) or minor (5-30%) levels.
One sample returned no DNA result in the tests as the meat ingredient had been so heavily processed it was marked down as denatured.
Last month the Guardian revealed that hundreds of food tests carried out by West Yorkshire councils had also found the routine adulteration of food and drink. Over a third of nearly 900 samples collected in that area were not what they claimed to be or were mislabelled in some way.
The regulator, the Food Standards Agency, which defines any level of DNA of undeclared species of over 1% as “gross adulteration”, said the failure rate found by Leicester and West Yorkshire is higher than the picture overall because its sampling programmes were targeted at categories of produce where problems are already suspected. The overall failure rate for meat in 2013 in local authority testing held by the FSA was 13.5%, it said.
It added: “The Food Standards Agency and Defra are helping target local authority resources through greater central coordination of intelligence, giving additional support for complex investigations, and additional funding. The government has increased support to the national coordinated programme of food sampling by local authorities from £1.6m to £2.2m in 2013-14.”
Leicester city council’s head of regulation, Roman Leszczyszyn said trading standards officers had been encouraged by central government to pursue a policy of intelligence-led enforcement rather than random sampling to “reduce the burden on business and remove unnecessary inspection”.
“That’s led us to look to the Food Standards Agency for intelligence. Meat composition has never come up on our horizon before,” he said.
In line with other authorities, Leicester Trading Standards has seen a steady reduction in resources, with the number of officers employed reduced from 31 in 1997 to 14 currently. Official figures, released in response to a parliamentary question from Labour MP for Bristol East Kerry McCarthy, show that the number of tests carried out by local authorities to check the composition of food roughly halved between 2008-9 and 2012-13. Five years ago 32,600 products were tested to check their composition, but last year just under 17,000 were tested.
Leicester council undertook the sampling programme after the horsemeat scandal when it discovered that lamb burgers being served in local schools and labelled as halal in fact contained undeclared pork DNA. Although its subsequent tests uncovered widespread adulteration with the wrong species, it did not find any other cases of undeclared pork or of horsemeat.
Professor Chris Elliott, who has been commissioned by the government to review the food system in response to the horsemeat scandal, warned that the Leicester results showed takeaways and butchers were still open to deliberate adulteration. “It’s clear that big retailers have put good measures in place now against species substitution but it’s also clear some places are very vulnerable. It is of paramount importance that local authorities conduct regular scrutiny of outlets in their areas,” he said.
In the West Yorkshire findings, illegal examples included mozzarella that was less than half real cheese, ham on pizzas that was either poultry or “meat emulsion” instead of pork, frozen prawns that were 50% water, minced beef adulterated with pork or poultry, fruit juices that contained illegal additives, counterfeit vodka, and a herbal slimming tea that was neither herb nor tea but glucose powder laced with a withdrawn prescription drug for obesity at 13 times the normal dose.