A MAJOR investigation has been launched by the Environment Agency after two separate pollution incidents on the Rivers Dane and Weaver.

Around 50 fish died in Middlewich as a result of pollution seeping from the River Croco into the River Dane on Croxton Lane.

Then teams from British Waterways and the Environment Agency were called out as oil spilled into the River Weaver, off a Winsford industrial estate, and spread to Northwich.

As a result of that incident four swans were covered with oil and were taken to Stapeley Grange Animal Hospital in Nantwich by RSPCA representatives.

Sue Lane, British Waterways Wales and Border Counties service manager, said the first priority was to contain the oil, which began entering the Weaver Navigation from a culvert.

The culvert drains a large area of Winsford including numerous industrial sites.

British Waterways staff and specialist contractors have now installed a containment boom across Vale Royal Locks and this will prevent further contamination downstream.

In addition, work is being carried out at the point of entry to the river to prevent further oil entering the waterway.

Ms Lane said: "Teams from the Environment Agency and British Waterways attended the scene but the full impact could not be assessed in the darkness.

"We have worked throughout the day with our specialist contractors to contain it. We have closed the Weaver Navigation to boating traffic from Hunts Lock upstream to Winsford while we work to stabilise the situation and begin the clean-up."

Meanwhile Richard Terrace, from Northwich Anglers' Association, said the pollution had disrupted a competition at the weekend.

He said: "This week's open was badly affected by the oil spill with several anglers not turning up and the rest of the match having to be moved down the river."

Steve Beech, from Middlewich, who is the secretary of Winsford Angling Association, said: "We have two major incidents even though we are in 2005. The public needs to be vigilant."

An Environment Agency spokesman added: "We are confident that we have the spillage under control and that it has not spread any further.

"Investigations are continuing while we try to find the source of the Winsford oil leak.

"Once we find out who is responsible we could take legal action."