The Northern Ireland Environment Agency is investigating a major fish kill near Claudy.
A spokesman for the Department of Agriculture, Environment and Rural Affairs said NIEA was first alerted to the incident on Tuesday.
“Staff were immediately tasked to investigate, and carried out an investigation through the evening, which has continued today (Tuesday) when dead fish were found,” said the spokesperson.
“Staff from Loughs Agency were informed and are working closely with NIEA to quantify the number and species of fish affected, and the cause.
“The latest available figures are that in excess of 1,000 fish of a range of species have been killed over several kilometres of river.
“However the assessment of the fish kill is still ongoing. Investigations into the cause of the pollution are continuing.
The latest available figures are that in excess of 1,000 fish of a range of species have been killed over several kilometres of river.DAERA spokesperson
“Where anyone notices pollution they can report this through NIEA’s 24-hour Pollution Hotline (0800 807060).”
Lucan Newland from Claudy was with a friend walking along the River Faughan when he said he noticed, at first glance, dozens of dead fish. He said it was a shocking discovery.
“For every step I took there were dead fish. It seems to be a 100 per cent kill. Nothing seems to have survived,” Mr Newland told the ‘Journal’. “It was bad, like something out of a horror movie; dead fish everywhere.”