A mysterious chemical that has turned a stretch of the Great Ouse river into a giant bubble bath has prompted a warning for dog walkers and anglers to keep away.
Environment agency officials are investigating the pollution, which is understood to be a form of detergent.
Hundreds of fish have been killed by the dense foam on the water, which residents describe as “like a washing machine has exploded”.
The environment agency experts say they do not believe the chemical is dangerous to humans, but warn that livestock and pets should be kept away as a precaution.
They say there is little they can do to clear the pollution, which affects the stretch between Brackley and Milton Keynes.
“As it travels downstream, it should become more dilute,” said a spokesman.
It is believed at least 800 fish have been killed by the mysterious foamy substance. Experts think it leaked into the Great Ouse at Brackley and flowed downstream to Milton Keynes.