Milk from two diary farms in Northern Ireland has been stopped from entering the market after test results showed the produce contained levels of dioxins above legal limits.

The Food Standard Agency said yesterday that the health risks to consumers were low and that it was not yet calling for any products to be withdrawn from shelves.

The news comes after separate alerts towards the end of 2008 over the contamination of Irish pork and beef with dioxins. The regulator concluded that meat products contaminated with the chemicals were likely to have reached consumers but posed little danger to public health.

“The FSA continues to monitor the situation and is in close contact with Government bodies in Northern Ireland,” the body said in a statement. “Contamination of the milk is likely to be from dioxin residues in the fat of animals that had previously eaten contaminated feed.”