People who bought unpasteurised milk at the Royal Welsh Show are being warned of potential food poisoning.

Officials are investigating the ’raw’ cow’s milk produced at Penlan y Môr Farm near New Quay in Ceredigion which was also available at last week’s Royal Welsh Show in Llanelwedd.

An investigation is already underway into four cases of the diarrhoea causing Campylobacter bacteria linked with milk from Penlan y Môr farm. The four cases all consumed or bought the milk at Aberystwyth Farmer’s Market after June 1 this year.

Public Health Wales said visitors to the Royal Welsh Show may have sampled or bought the milk, which was available there on Wednesday, July 26.

It, Hywel Dda University Health Board, the Food Standards Agency, and Ceredigion County Council are investigating the four cases already identified.

Anyone who may who have consumed unpasteurised milk from this farm experiencing persistent symptoms should contact Ceredigion County Council on 01545 572 105.

Any remaining unpasteurised milk that has not been consumed should not be used.

People with a weakened immune system are particularly vulnerable to food poisoning, and are strongly advised not to consume unpasteurised milk and cream. Vulnerable groups include pregnant women, infants, children, and older people.

Campylobacter is the most common bacterial cause of diarrhoea in Wales and the UK. Public Health Wales is notified of between 3,000 and 4,000 cases of Campylobacter every year in Wales.

Dr Brendan Mason, consultant in communicable disease control for Public Health Wales, said: “If you have consumed Penlan y Môr unpasteurised milk any time since June 1, including at the Royal Welsh Show on Wednesday 26 July 26, and you are experiencing symptoms of Campylobacter infection, we want to hear from you.

“The symptoms of Campylobacter are persistent nausea, diarrhoea, stomach cramps and a fever. Sometimes vomiting and bloody diarrhoea may also develop.

“It is a very unpleasant infection, and more serious complications can occur. As in any diarrhoeal illness, washing hands after using the toilet and before preparing or eating food is very important and anyone worried about their symptoms should seek medical advice.

“We will continue to monitor the situation.”

Anyone with concerns about their health should contact their GP or NHS Direct Wales on 0845 46 47.