An alert has been issued after the discovery of a potentially cancer causing drug in organic chicken.

Traces of a nitrofuran, a banned veterinary medicine, were found in certain batches of fresh chicken sold by supermarket chains Tesco, Waitrose and Morrisons.

All the meat concerned will now be beyond the use-by date but there are concerns some could have been frozen to eat at a later date.

The Food Standards Agency, which issued the warning, said anyone who has the chicken should throw it away or return it to the retailer.

The problem came to light during routine tests carried out by Northern Ireland’s Department of Agriculture and Rural Affairs (DARD).

The chickens came from a Northern Ireland farm and were supplied to supermarkets across the UK by Moy Park, a food processing company in the province.

The FSA said Moy Park was co-operating with an investigation by DARD officials into the source of the contamination.

It is illegal under EU law to use nitrofurans in food processing animals because it could increase people’s risk of getting cancer.

However, the health risk from eating the chicken is considered low because the danger comes with exposure to the drug over the long term.

All the chicken recalled have use-by dates of between October 8 and 14 and were sold as either chicken breasts, thighs, drumsticks, legs, wings, or whole birds.