An investigation is under way after oil and other pollutants flowed into a rare Norfolk chalk stream for several days.

The Environment Agency is attempting to identify the source of the issue and is currently analysing samples taken from the Gaywood River in the Bawsey area in West Norfolk.

Locals have said the problem has continued throughout the week and an absorbent boom has been placed downstream to contain the flow of the pollution.

A spokesman for Gaywood River Revival, a group campaigning to protect the waterway, said: "This could have serious repercussions to the river's ecosystem.

"The pollution is entering the river over a half mile stretch east of the Bawsey ruins.

"It could be oil, diesel or petrol and it is washing into the river, coating the surface with a film of oil that will cut off vital oxygen supplies to fish as well as contaminating the river banks and silt for years to come."

READ MORE: Pollution fears after burst pipe flows sewage into chalk stream

Eastern Daily Press: An oily sheen can be seen floating in the Gaywood RiverAn oily sheen can be seen floating in the Gaywood River (Image: Gaywood River Revival)

Environment Agency officers visited the site last week - three days after it was first spotted.

A spokeswoman said: "At the time of their visit the officers noted that an oil sheen was present on the water and took samples to be sent to the laboratory for analysis.

Eastern Daily Press: Pollutants flow along the Gaywood RiverPollutants flow along the Gaywood River (Image: Gaywood River Revival)

"An absorbent boom was later deployed across the watercourse by our operations team. Further water samples were also taken downstream and sent for analysis.

"We believe we have identified potential sources of the oil and are continuing with our investigations.”

Eastern Daily Press: Norfolk County Councillor Rob ColwellNorfolk County Councillor Rob Colwell (Image: Newsquest)

Norfolk County councillor Rob Colwell, who represents Gaywood South, feels frustrated more isn't being done to protect the river.

"This is absolutely disgusting," he said.

"it is not the first time there have been pollution events here. People want reassurance that the Environment Agency will take action. It is just awful."

Chalk streams are often described as England’s rainforests – unique habitats with the majority of the 200 in the world found in the southern half of England but these unique habitats are under threat due to pollution and over-abstraction.