We’re told healthy fish have been spotted swimming below a film of diesel in the River Wandle in Mitcham.

It’s after a spillage on Tuesday afternoon leaked around 4,000 litres of the fluid into the “at risk” chalk stream.

Any reports of swans covered in diesel should be reported to the Swan Sanctuary in Shepperton.

An investigation into what happened is being carried out by a number of authorities including Thames Water and the Environment Agency.