A ‘PRECIOUS’ chalk stream which runs through Wantage has been polluted, environmentalists say.

The Letcombe Brook was pictured with an ‘oil or petrol like’ substance last week. Mark Bradfield, the Letcombe Brook Project Officer, said: “The pollution affected at least 2km. Chalk Streams are very rare and support many rare animals such as the water vole, brown trout and bullhead.”

Mr Bradfield added: “Many people pour all sorts of stuff down drains and don’t realise it might then end up going straight into a river.”

He said the source had not been identified, since numerous drains empty into a pipe from the car park near Sainsbury’s which the pollution had been traced to.

A Sainsbury’s spokeswoman confirmed it was 'supporting' the Environment Agency (EA).

An EA spokesman said: "An EA officer found evidence of oil in Letcombe Brook when he visited the site on 16 January. He deployed absorbent booms to contain any further oil but was unable to trace the source.

"Returning the next day, he found very little oil odour and no oil residue in the vegetation. He concluded it was a relatively small spill. The absorbent booms were left in place for several days.

"Many drains empty into local rivers, and pollution incidents like these can be detrimental to wildlife. The Environment Agency is working with partners in the Letcombe Brook area to run an awareness campaign that will see yellow fish stickers posted near drains to remind people not to pour contaminants down the drain.

"Anyone noticing suspicious activity or pollution should call our free, 24-hour incident helpline on 0800 80 70 60."