Beef from around 28,000 cows that tested positive for bovine tuberculosis (bTB) are being sold for human consumption each year by the Department of the Environment, Food and Rural Affairs (Defra).
The raw meat, which is banned by most supermarkets and burger chains, nets the Government around £10m a year, an investigation by the Sunday Times has found.
While the likes of Tesco won't buy it due to "public-health concerns surrounding the issue of bTB and its risk to consumers", the beef is being sold to some caterers and food processors and finding its way into schools, hospitals and the military, or being processed into products such as pies and pasties.
Burger King, McDonald's, Sainsbury's and Waitrose are among the other major companies that reject the meat but some of Britain's largest catering firms, including Sodexo and Aramark, could not offer similar assurances.
Foodservice giants Aramark and Compass Group said that its food complied with the standards set by the FSA but would not confirm whether or not they accepted meat from TB-infected animals.
A spokesperson for Aramark said: "All meat provided by Aramark is fit for human consumption, abides with all UK government legislation and is tested in accordance with its policies. Our meat supply partners are BRC (British Retail Consortium) accredited and are regularly audited by NSF-CMI, a leading food safety organisation."
Compass Group released this statement: "All of our suppliers have to adhere to robust food quality, safety and hygiene standards. We only source meat from companies that comply with all relevant legislation for the production of meat products and that only use food which has been passed fit for human consumption, in line with AHVLA and Food Standards Agency testing guidelines."
Sodexo could not be reached for comment at the time of publishing.
Defra, which sells the meat without anything to warn processors or consumers that it comes from bTB-infected cattle, said in a statement: "The risk to consumers from eating meat from TB reactor animals is very low."
M bovis, the bacterium that causes bTB, can survive cooking up to 60C.
But the organisation's own experts have claimed that levels of bTB in cattle are becoming a serious threat to human health, citing it as the justification for a cull of tens of thousands of badgers which, they say, help spread the disease between cattle.
"If we do not maintain and improve our bTB controls… the risk of infection to other mammals and humans will inevitably increase," said Defra's chief vet Nigel Gibbens recently.
There are two main forms of tuberculosis, with human TB accounting for around 9,000 UK cases a year. The bovine strain is diagnosed in around 40 people annually. But only about 60% of all TB victims are tested to see which strain is responsible, so the real number of people suffering bTB is estimated to be at least 70 a year.
Public Health England (PHE) said that for every person who develops the disease, another 10 become infected but never develop symptoms, suggesting 600-700 people are infected by M bovis each year.
PHE's website says: "Transmission of M bovis can occur between animals, from animals to humans and, rarely, between humans. Transmission is most commonly by the aerosol route but also through the ingestion of milk and meat from infected animals."
Owen Paterson, the secretary of state for environment, food and rural affairs, reinforced this in a recent interview with the Sunday Times in which he said: "This disease is a zoonosis. It can transfer to human beings and kill human beings. This disease killed a lot of people in the 1920s and 30s before we pasteurised milk."
The UK government bought and slaughtered 31,615 cattle in 2011, after they tested positive for bTB. Of these carcasses, 88% was deemed fit for human consumption and went into the food chain. The testing of cattle and compensation for farmers costs taxpayers about £80m a year and Defra's £10m income from the carcasses is used to offset this.
According to the Food Standards Agency (FSA), carcasses from infected animals were subjected to a close visual inspection and infected areas removed before the meat was consumed. But the meat is not subjected to any microbiological tests.
"When a tuberculous lesion is found in the lymph nodes of only one part of the carcass, then that part and the associated lymph nodes are declared unfit for human consumption," said the FSA. "The remaining meat is considered safe to enter the food chain."
However this statement is in conflict with scientific research that found that meat can contain bTB bacteria. Ricardo de la Rua-Domenech, a Defra researcher specialising in TB wrote in a 2005 key paper in the journal Tuberculosis: "Whether TB lesions are detected or not, it is possible for apparently normal skeletal muscle (meat) of infected cattle to contain bacilli." The risk of human infection was still low, he suggested, partly because meat was usually cooked.
Bovine TB can take years or even decades to develop, so it is hardly ever possible to say whether any one person was infected by milk, meat or contact with animals.