DOZENS of swans that have died in the past year on a stretch of river may have been deliberately poisoned, a vet has said.
Wildlife experts, the Environmental Agency, the RSPCA and police are investigating what has been killing the mute swans on the Wear, at Chester-le-Street, County Durham.
Vet Gill Maxwell, who has sent 20 dead swans off for tests, said she has never seen anything like it in more than 30 years in practice.
Of the tests that have been completed, all have reported extremely-high lead levels.
One bird showed 215 parts of lead per million in its kidney, and 127 in its gizzard. Levels of 10 per million are considered toxic, she said.
It may be that lead levels in the river sediment have suddenly increased, but Environment Agency tests have not picked up any significant change.
Miss Maxwell, who runs Cestria Veterinary Centre, said: “We are reluctantly coming to the conclusion this may well be a deliberate poisoning, although at the moment we cannot confirm that.
“Unfortunately there is a section of the public who do like to destroy beautiful things.”
About 100 swans live on the Wear in Chester-le-Street’s Riverside Park.