EXPERTS were today continuing to probe the death of 800 fish in a river.
As this website reported last night, the pollutant was found in the river Ebbw Fach between Abertillery and Six Bells following reports from members of the public at the weekend.
The Environment Agency was called in to investigate the spillage, which is believed to be some kind of detergent that seeped into the river in Abertillery.
By the time it reached Six Bells it lost its power to kill, but had affected about a mile of the Ebbw Fach.
Agency officers began investigations, following a report of dead fish, mainly trout, at 9.20am on Sunday morning.
Agency Environment Officer Ashley Lansdown said: "We have had similar incidents downstream on the River Ebbw at Crumlin in the recent past but were unable to find the source of the substance even with the help of the local authority in searching the drainage system."
During the late summers of 2003, 2004 and 2005 there were pollution incidents from the Crumlin Culvert on the River Ebbw, which resulted in thousands of dead fish.
But the agency said last year it started "rigorous monitoring" at two industrial estates that drain into the culvert, and there have been no further pollution incidents to date.
Mary Rice of Aberbeeg River Rangers, who help keep the river free of rubbish just a mile down stream, said: "It's a terrible thing to happen."
"I remember when I was younger this river was known as the stinky because of all the contamination from the pits. Now its been cleaned up and the fish are back, and this happens."
Anyone with information on the latest incident can call the agency's emergency hotline free and confidentially on 0800 80 70 60.