10 August 2012 Last updated at 10:43 ET

'Deliberate' pollution kills 3,000 fish in Burniston

The Environment Agency said the pollution had a "rapid impact" on the watercourse

Almost 3,000 fish died in a North Yorkshire beck after "serious pollution" believed to be a deliberate act said the Environment Agency (EA).

Burniston Beck, near Scarborough, was polluted and the EA is appealing for information.

Dead fish were first found near Rocks Lane, Burniston, and scientists took water samples to try to determine the cause of the pollution.

Stephen Richardson, of the EA, said: "We will not hesitate to prosecute".

Mr Richardson said the pollution may have started in the Lindhead area and had "a rapid impact" on the downstream watercourse.

There was no indication of what the pollutant was or what caused the fish to die he added.

The incident was confined to the beck, although over 800 brown trout were killed.

Live fish are swimming in the beck and the quality of the water is now very good said the agency.

An ecological survey showed invertebrates - beetles, shrimps and other creatures - appear to have been unaffected.

A survey to determine the number of fish remaining in the beck is to be carried out.