A Competition Authority ruling that allows it to "veto" the lawyers chosen by any party it is investigating could be a breach of human rights, an expert in the field warned yesterday.

Mr Vincent Power, a partner with solicitors' firm A&L Goodbody and a leading practitioner in competition law, told a conference that the monopolies watchdog had introduced a regime that effectively allowed it veto lawyers chosen by companies and individuals that it was investigating.

Mr Power compared it to a situation where one motorist in dispute over a road traffic accident was able to prevent the other motorist from choosing his or her own lawyer.

"It is extraordinary that one party to an investigation - the Competition Authority - could purport to effectively choose who is the lawyer for the other party to the investigation," he said. "There is a very, very strong argument that this could be a breach of the European Convention on Human Rights."

He pointed out that this protected the right of anyone under investigation to choose their own lawyer and said that this right would extend to companies and businesses.

Mr Power argued that any dispute over possible conflicts of interest, which the authority said the ruling is designed to prevent, should be a matter for the courts and the bodies that regulate both the State's legal professions.

He also said that the ruling could lead to increased costs for businesses involved in an investigation, either directly or as witnesses, because it effectively created more work for lawyers.

However, Competition Authority director Mr Terry Calvani yesterday denied that it was trying to impose a veto on individuals and companies choosing independent legal advice. He said the ruling stated that it would refuse to enter talks or discussions with lawyers where it felt there was a conflict of interest.

"For example, there is no way that a lawyer, be they a solicitor or a barrister, could act for two parties in one investigation where one of them has joined our immunity programme [which protects whistleblowers from investigation\], and one of them has not," he said.

However, Mr Calvani said that this was "an extreme example" and that the ruling was not limited to this situation, and could be invoked in other circumstances.

He said that the authority was primarily concerned with protecting the integrity of the investigation process, because it feared that otherwise successful convictions for breach of the competition code could be overturned if defendants could successfully claim that their legal advice was not independent.

He added that it could not prevent people from going to court to challenge its decisions.