The Environment Agency said the fish had been discovered at Barrack Brook, Stukeley Meadows, in Huntingdon. A spokesperson said officers have taken samples to identify the source of the pollution. "Until we've identified what the pollution is, we advise the public to avoid contact with the water." The Hunts Post has contacted the Environment Agency for comment. Get in touch at oliver.murphy@newsquest.co.uk or newsdesk@huntspost.co.uk