Diseased cattle, slaughtered after testing positive for bovine tuberculosis (bTB), are being sold for human consumption by Defra, the food and farming ministry has said.

The raw meat, from around 28,000 diseased animals a year, is banned by most supermarkets and burger chains, The Sunday Times reported. Tesco, for example, rejects it because of "public-health concerns surrounding the issue of bTB and its risk to consumers".

But it 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, the newspaper said.

A Defra spokeswoman said: "All meat from cattle slaughtered due to bovine TB must undergo rigorous food safety checks before it can be passed fit for consumption. The Food Standards Agency has confirmed there are no known cases where TB has been transmitted through eating meat and the risk of infection from eating meat, even if raw or undercooked, remains extremely low."

The meat is sold with no warning to processors or consumers that it comes from bTB infected cattle.

Asked whether the public should know whether or not the meat they are buying originated from an infected cow, a spokeswoman for the Food Standards Agency said: "All meat must be marked with an identification mark which will indicate the approval number of the plant of origin."

"However, meat from TB reactors, once it has been passed as fit for human consumption, is not required to be marked in any way to distinguish it from other meat. Meat which passes the post mortem inspection is fit for human consumption and does not need additional labelling."

If an inspection of a carcass reveals tuberculous lesions in more than one organ or region it is declared unfit for human consumption and destroyed, she explained. But if only the lymph nodes in one organ or part of the carcass is infected, then that area is removed and the rest is considered safe to enter the food chain.

She added: "Cooking this meat would be an additional safety step, but we would emphasise the risk even before cooking is very low."

The Sunday Times reported that Defra's reassurances contrasted with experts' warnings who have said rising levels of bTB in cattle are becoming a serious threat to human health. Such claims have been used to justify a cull of tens of thousands of badgers which, are said by some, to help spread the disease between cattle.