A STOKE-ON-TRENT firm is at the centre of a major pollution inquiry after a cyanide leak destroyed the fish population along part of the River Trent.

Wildlife experts today predicted it will take up to five years before the environmental impact of Tuesday's pollution scare is overcome.

The warning came as the Environment Agency (EA) stopped hazardous waste firm Red Industries from discharging industrial effluent into the sewer system.

Tests showed the colourless, odourless cyanide was present in a sewer discharge point used by the Burslem company which collects, recycles and disposes hazardous industrial waste, asbestos, aerosols and solvents.

EA manager David Hudson said: "The pollution has killed thousands of fish and caused a great deal of concern.

"This sort of incident is unacceptable. Our investigation is continuing to ensure we can take firm action against those responsible."

Under the Water Resources Act it is an offence to cause poisonous matter to enter rivers and any company found responsible faces an unlimited fine.

A spokesman for Red Industries, on Sandbach Road, Sneyd Industrial Estate, said: "The Environment Agency has asked us to cooperate.

"Red Industries has voluntarily stopped discharging any industrial effluent to the sewer via our licensed facility while the investigation is carried out.

"Since the voluntary action the Environment Agency has formally served Red Industries with a notice of suspension until specific steps have been taken to remove any risk."

Latest samples taken from the river between Stoke-on-Trent and Yoxall show the pollution has diminished.

Now EA officers will carry out biological surveys to determine the long-term impact.

The river banks are home to kingfishers, mink and otters.

But the pollution is likely to enter the food chain as vegetation and invertebrates have all been affected.

Staffordshire Wildlife Trust conservation manager Sue Lawley said: "In the environment, sewage breaks down relatively quickly into less harmful chemicals.

"But cyanide breaks down into cyanide compounds, which although less harmful, are often still very toxic and may persist for a long time. There is evidence that some compounds are stored in plant and fish tissue.

"The dead fish must be disposed of very carefully because birds and mammals may feed on them. The knock-on effect could last as long as five years."

Counting the cost: See Page 6