Meat produced from British pigs has been shown to be infected with a livestock strain of MRSA.
According to a Guardian and Bureau of Investigative Journalism report, pork products bought at Asda and Sainsbury’s were contaminated with the bug.
The two outlets had tested 97 samples of pork from British supermarkets, with three found to be contaminated.
The investigation has also established that a loophole in import regulations is leaving an open door for MRSA CC398-infected live pigs from countries such as Denmark, where the disease is rife.
Experts are warning that if no action is taken, the UK’s pig herd could rapidly become infected.
Such an epidemic could have a serious impact on human health, according to leading Danish microbiologist and MRSA expert, Professor Hans Jørn Kolmos.
The superbug, like other foodborne germs, is killed by thorough cooking - but it can be passed on through lapses in hygiene.
Workers on pig farms can also catch the disease from infected animals and pass it on to other people.
'Hugely concerning'
Emma Rose, the Alliance to Save our Antibiotics, said it is "hugely concerning" that livestock associated MRSA has spread from British farms into the domestic pork supply chain.
"If we are to have any chance of heading off this catastrophe, the government needs to put in place some basic measures to tackle the spread of LA MRSA and introduce immediate screening of the national pig herd, as well as strict testing of imported livestock and meat products," Miss Rose said.
"Crucially, we need immediate restrictions introduced to farm use of antibiotics most linked to LA MRSA - particularly the ‘critically important’ modern cephalosporin and fluoroquinolone antibiotics."
In a statement, the Department for Environment, Food and Rural Affairs (Defra) said: “Livestock-associated MRSA is not the same as MRSA strains that can cause healthcare-associated infections and if meat is handled and prepared properly the risk to people is low.
"Defra and the National Pig Association recommend that pigs imported to Britain are screened for LA-MRSA.
"The government is reviewing options for surveillance, which will be proportionate to the very low health risk posed by livestock-associated MRSA."
