The find is being called vitally important by experts in understanding the endangered species.

A guide has told of the “hugely exciting” moment one of his groups discovered a rare species of fish near Coventry.

Alex Jones, from the Warwickshire Wildlife Trust, was taking members of the public around the River Sherbourne when somebody pointed out what he realised was a critically endangered European eel.

The find was made on 7 September, the first day of Coventry’s River Festival.