RAW sewage overflowed out of a blocked drain yesterday and straight into a brook.

Thames Water said the drain next to Boundary Brook, in Mileway Gardens, Headington, became blocked on Friday and again yesterday.

An Environment Agency officer was last night investigating if the leak had killed any wildlife, as the brook flows through the Lye Valley Nature Reserve.

Engineers were called out to the drain on Friday to initially clear the blockage, and returned on Saturday to check it.

However, yesterday the water company was contacted again regarding the drain and engineers discovered there was another blockage.

A spokesman for Thames Water said: "Unfortunately the blockage has resulted in some pollution to a nearby stream, which has been reported to the Environment Agency.

"We will now be carrying out an investigation to see what the cause of the blockage was. We apologise to residents for any distress this might have caused."