SCORES of fish have been found dead in a stretch of the River Skerne, leaving environmental experts baffled.

Officers from the Environment Agency were called to Darlington at the weekend to examine fish found dead on the river bed between Skerne Bridge and Haughton Bridge.

The majority of fish have been found at Five Arches Bridge, but others have been spotted along a kilometre-long stretch of the river.

The cause of what appears to be poisoning, is as yet unknown, and environment officers have confirmed that whatever killed the fish is no longer in the river.

An Environment Agency spokesman said: "There's no evidence of pollution in the stream at the moment, so whatever has killed these fish is no longer in the water.

"It's centred in the Five Arches Bridge area of the River Skerne. Our fisheries officers have checked upstream and downstream and our inquiries are continuing.

"They have been trying to find the cause of the deaths, but it does appear to be an isolated case.

"We were informed by a member of the public and we were subsequently called by the police. There appears to have been a case of pollution."

Although officers said they were still unsure what type of fish had been killed, local residents are convinced the majority are stock trout.

Bill Mooney, who lives near to the river, said he spotted dozens of dead trout as he went for a walk.

The 66-year-old said: "I fish myself and I've just come back from a trip to Scotland and I never saw any trout as big as this.

"There are dozens of them all along a small stretch of river. They look like stock trout because they are big and fat, and must have been released into the water, because they would be thinner if they had grown in the river.

"Some of the dead fish are chub, which are quite hardy, so whatever has killed them must be pretty toxic. It's disgusting if it is pollution, because a lot of work has been done to clean the river.