The Environmental Protection Agency (EPA) is investigating a spillage of sludge from a distillery into Cork harbour last Friday.
The EPA received notification from Irish Distillers, Midleton, Co Cork on Friday of a discharge of approximately 360m 3of sludge into a sewer.
An EPA inspector from the Cork office has carried out an initial inspection of the site.
Irish Distillers said it had identified the source of the problem as a coupling and monitoring failure and had rectified it.
The sludge, comprising organic matter and suspended solids, was discharged at Rathcoursey Point, Cork Harbour, instead of clean, treated water from the distillery.
EPA personnel from the Cork office and officials from Cork County Council have been on site and the EPA investigation into the incident is on-going. Cork County Council's water quality investigation found no toxicity levels in the water.
The Fisheries Board have also been notified.
EPA inspectors will prepare a full report on the incident in due course.
In a statement the EPA said it was a priority "to ensure that the necessary management practices are in place to eliminate the causes of this type of incident and protect the environment".
investigation into the incident is ongoing. The Fisheries Board has also been notified.