A precautionary swimming ban is in place at Sandycove Harbour in Dublin following the detection of high levels of E Coli.

In a statement this evening, Dun Laoghaire Rathdown County Council said the cause of the high levels remains unknown.

An investigation is currently underway and the water is undergoing re-testing.

Authorities will remove the temporary ban if the results of the re-tests are acceptable.

E Coli is a bacterium commonly found in the lower intestine of humans and animals.

If confirmed, its presence would suggest that the water has been contaminated by faeces.