Reports of a river of raw sewage pouring through pebbles on to a section Brighton beach are being investigated by the Environment Agency.

Surfers against Sewage, (SAS) whose members surf all year round from the beach immediately to the west of Brighton's West Pier, have witnessed a stream containing what they believe is raw sewage cutting a channel in the pebbles.

The high tides and rough seas of recent days have covered the offending channel but the Environment Agency is taking the complaint seriously and asking beach walkers and surfers to report it, should any sewage reappear.

Richard Gregory, a director of the national SAS campaign and a regular surfer from the beach, said: "At low tide in calm conditions, you can actually see raw sewage coming up through the pebbles.

"It is a torrent of water cutting a gully in the beach. It smells and is revolting. If this was the middle of summer there would be a terrific outcry and the beach would have to be cordoned off.

"Several of our members who regularly surf off the beach have felt unwell recently and they put it down to the state of the sea close to the West Pier.

"I have reported the matter to the Environment Agency and when they came down to investigate they could smell it but because of the high tides, the channel was not visible. I am pleased they are taking this seriously."

Jo Hunt, a spokeswoman for the agency, confirmed an investigation was taking place. She said: "We have not seen any evidence so far.

"We will continue to investigate. We are appealing for anyone who sees any raw sewage suddenly appearing in this area of the beach to phone our hotline."

A spokeswoman for Southern Water said officials had investigated the claim raw sewage had been seen on the beach and found nothing.

"We do not have outfalls in this area and there is no reason to connect it with any of Southern Water's operations."

To contact the Environment Agency, call the hotline on 0800 807060.