The Competition Authority has begun an investigation into the waste sector in Mayo following claims that the business was being carved up for private firms in areas of county by Mayo County Council.

Officers from the authority visited the head office of the county council in Castlebar last February and demanded immediate access to any relevant records or files. Around the same time, officers raided the business premises of around five waste companies in pursuit of any evidence that might back up the claims. The names of the companies in question are not known.

The ongoing investigation arises from information received by the authority and the raids were carried out on foot of warrants issued by a district court judge.

The authority would have been obliged to make a case to the judge in question that the issue of warrants was appropriate given the information available to it.

It is open to the authority to prepare a file for the Director of Public Prosecutions, to pursue the matter in the civil courts or drop the case altogether. Because the investigation is still in its early phase, it is understood that no decision has been reached as to next move.

The investigation is unusual as it involves an examination into whether a public body - ie the county council - was in breach of the law.

Under scrutiny is a detailed allegation that the council allocated the waste market in parts of the county to individual companies, which were then alleged to have operated effective monopolies in their own specific areas.

The absence of competition in a sector frees a monopolist to charge higher prices than could be charged if rivals were competing for the same business. If proved, that would amount to an unlawful restriction of competition in the area in question.

News of authority investigation emerged in today's edition of the Free Mayo Echo, a freesheet. John Condon, the Mayo county secretary, declined to comment on the investigation and said he had not seen the report. "We're not commenting at all," he said.

Competition inquiries can continue for years before they reach their conclusions. Ongoing proceedings in a recent case against the alleged members of cartel that colluded to fix the price of home-heating oil in Galway relate to events in 2001 and early 2002.

Price-fixing charges last week against a Cork-based Ford dealer follow a 2003 inquiry.