The Office for Environmental Enforcement is to seek information from Galway County Council about the cause of a serious deterioration in the quality of bathing water at one of the county's top beaches.
On Tuesday the European Commission published a report which showed that the main beach at Spiddal was one of four in Ireland which failed to meet basic water quality standards.
Yesterday locals claimed the cause of the pollution was from a sewage pipe which was built and is operated by Galway County Council.
Spiddal is one of more than 70 beaches in Ireland which was awarded a Blue Flag status for clean water and an exemplary clean environment.
The beach, one of the largest in Co Galway, is expected to lose its flag status when the 2004 list of Blue Flag beaches is published on Tuesday. However, locals claim that raw sewage, including sanitary pads, can sometimes be seen at low tide.
A spokeswoman for the Environmental Protection Agency, which published figures on water quality for 122 beaches in Ireland yesterday, said the Office for Environmental Enforcement (OEE) would be writing to all four local authorities where water quality failed, including Galway County Council.
Keem beach on Achill Island, Balbriggan beach in Dublin and Bray beach in Co Wicklow also failed to reach minimum standards. The OEE has the power to prosecute any local authority it believes has not taken adequate measures to protect the environment.
Yesterday community leaders called for a full investigation into the cause of the pollution. They rejected any suggestion the pollution came from agricultural sources.
"A sewage pipe built by Galway County Council has led to a build-up of deposits," according to Mr Seán Ó Coistealbha, a member of Spiddal Parish Council.
Galway County Council declined to comment on the cause of the pollution. "We still haven't seen the report which has been in the papers," a council spokesman said.
The EU report is based on water tests carried out by the council's staff.
The spokesman acknowledged that the council was aware of a water quality problem at Spiddal beach since last year. He said the council was already "taking action" but declined to say what that action was.