The Yare Valley Society, a group of volunteers who work to maintain the Yare Valley as a place of enjoyment, were made aware of the spill last week.

They reported it to the Environment Agency, who subsequently launched an investigation.

The agency, which is responsible for land regulation, floods, waste management and conservation, cannot say exactly where the spill happened while the investigation is ongoing.

However, it has confirmed it is looking into an area in western Norwich.

© Norwich Evening News