Thames Water investigated over Eton Wick sewer flooding
Thames Water is being investigated by the Environment Agency after pumping sewage into a village watercourse.
Waste water was pumped into Roundmoor ditch, Eton Wick in Berkshire in January after rainfall inundated the sewer network in Slough.
The pollution led to the death of fish, as well as water with "clear evidence of solids", according to residents.
Sarah Sharpe, of Thames Water, said the discharge was made under exceptional weather conditions.
She added: "We're really sorry to people living nearby.
"Although undesirable, this is the normal, permitted practice in such exceptional weather conditions and prevents sewage backing up in the pipes and coming out into people's homes."