Scientists have discovered a new strain of the MRSA “superbug” in the milk of British cows, research published today says.

Experts have ruled out any general threat to the safety of milk or dairy products, but they point to “circumstantial” evidence of the bacteria passing between cattle and humans.

A small number of infections and minor conditions have since been reported but health officials have played down the risk to the wider population.

Dr Mark Holmes, the Cambridge University veterinary scientist who led the research, and his team stumbled on the new MRSA bug while investigating mastitis, a potentially lethal disease which affects dairy cows.

It is the first time evidence of MRSA has been found on British farms.

A Department of Health spokesman said: “From the available evidence, we understand this new form of MRSA is rare in the UK and is not causing infections in humans. However our expert committee (Advisory Committee on Antimicrobial Resistance and Healthcare Associated Infections) will be reviewing this issue at their next meeting and will consider potential medical, veterinary and food safety issues.”

The research is published today in The Lancet.