An investigation is underway into a large fish kill on a major angling waterway, the Clodiagh River.
Inland Fisheries Ireland has said it responded to reports of a pollution discharge last Tuesday on the tributary of the Tullamore River.
So far, 3,700 fish have been found dead, including trout and salmon.
Inland Fisheries is investigating a discharge of chemicals from a specified location and is following a definite line of inquiry.
Speaking on the pollution Inland Fisheries Ireland Director, Amanda Mooney appealed for information on the pollution discharge.
“This pollution discharge has been a devastating blow to the River Clodiagh,” said Mooney
“The quantities of fish present would indicate that the river had recovered considerably in recent years from a previous eutrophication state, with excellent salmonid spawning and nursery habitat. We are asking the public to report any suspected discharge into any river immediately to the IFI 24 hour confidential hotline 1890 34 74 24.”