The Gelly Burn in Dundee is at the centre of a pollution scare after sewage was found in the waterway that flows through Caird Park.
Scottish Water confirmed the problem, which was reported to them at the weekend.
A spokesman said: “We are aware of this issue and are investigating the matter to establish the cause.
“We will complete any clean-up operation that is required in liaison with the Scottish Environment Protection Agency.”
Sepa confirmed it received a complaint about pollution at the Gelly Burn.
“A Sepa officer visited the site in question and confirmed there was evidence of sewage in the watercourse.
“Sepa has since contacted Scottish Water and requested an investigation to be carried out. We will continue to liaise with the agency to see the issue resolved.”
The pollution was reported by local man John Richmond, who found it when he was out walking his dog.
“I suspected for a while that the water smells of sewage and I contacted Sepa,” he said. “They sent an inspector who confirmed the smell of sewage. Sepa referred this to Scottish Water.
“I’ve just walked to the Old Glamis Road end of Caird Park where the Gelly Burn flows out from a culvert. The sewage there is obvious and the water is disgusting.”
He continued: “I think there should be some signs up warning the public in the area that the water is contaminated. No one should go near the water while there is this problem.”