Inland Fisheries Ireland are investigating a recent incident in County Cavan where over 150 fish were killed.
Officers from the North Western River Basin District were alerted to the scene in the Ballinagh River on July 19th.
Inland Fisheries say they are not in a position to comment on the cause, water samples have been taken for scientific analysis.
Anyone with any information is asked to contact the organisation's 24 hour hotline on 0818 34 73 24.
