A deadly chemical found in a Leigh brook has angered local anglers.
Poisonous arsenic has been detected in Westleigh Brook between Pennington Flash and Pennington Park, along with zinc and copper.
The revelations were made in a major draft report for the European Water Framework Directive (WFD), which aims to achieve "good" status in all north west waters by 2021 or 2027.
Westleigh Brook flows in to the River Glaze, where traces of arsenic, zinc and copper have also been found.
One fishing club member from Leigh said: "I've heard rumours about something like this and from our point of it's very worrying.
"That stretch of water has historically been very popular with anglers but it's not anymore, although at this stage we can't say for sure why that might be."
Lancashire Fisheries Consultative Association (LFCA), which represents Leigh and Wigan fishing clubs, is calling on all anglers to make sure that they have their say in shaping the future of river and stillwater fisheries.
LFCA secretary John Weedon said: "I have been highlighting the Glaze's pollution problems for the past few years, particulary on some grim storm sewerage overflows.
"WFD may be well intentioned but it's scandalous that lethal arsenic is being allowed to enter water courses given we are in an area of so-called cleaner rivers.
"I've known the Glaze since the 60s and it's lost countless tens of thousands of fish since then. It's the forgotten river that refuses to die.
"There was a serious fish-kill down the Glaze a number of years ago when the trouble source apparently came down Westleigh Brook. A friend was fishing at the time and got in touch with Environment Agency when dead fish came floating past.
"No one was prosecuted and apparently just a warning letter was sent to a firm, which has caused anger and outrage among anglers in Leigh."
To register views on the future of Leigh's waterways, visit leighreporter.co.uk