The Court of Appeal has cleared the way for an investigation by the Standards in Public Office Commission into the alleged duplication of expenses claims by Fianna Fail Senator Brian Ó Domhnaill.

The three-judge court on Friday rejected an appeal by the Senator against the High Court’s dismissal of his challenge to the investigation concerning travel and subsistence claims made by him between 2006 and 2007, when he was a member of Donegal County Council.

The Commission was due to begin a public session concerning the expenses matter in June 2012 but that was put on hold after Mr Ó Domhnaill secured leave from the High Court days earlier to bring his challenge.

In his judicial review proceedings, Mr Ó Domhnaill claimed the Commission was not entitled to deal with the matters because, he claimed, they arose from an anonymous complaint by a member of the public.

Alternatively, he sought orders requiring the case to be heard by a Commission comprising members who are bilingual and able to conduct and understand the proceedings without the assistance of an interpreter.

Unless the tribunal is bilingual, his rights as an Irish speaker will be infringed, he claimed. He would be disadvantaged if an interpreter is necessary to translate the evidence and submissions given on his behalf in Irish as translator evidence is not similar to direct evidence, he argued.

In opposing the case, the Commission and State contended the complaint being investigated concerned alleged duplication of expenses claims and the investigation is in the public interest.

The Commission said the complaint before it was made in a letter dated May 28th, 2012 sent to it by the Mayor and County Manager of Donegal County Council following their investigation of a referral made to them by the Ethics Registrar of the Council.

While the Commission acknowledged that information in an anonymous letter had prompted the Ethics Registrar to examine matters, it argued the complaint being investigated by it was not a referral of that anonymous letter by the Mayor and County Manager but rather a complaint by those men arising from their view certain specified acts set out in their report may have been done by Mr Ó Domhnaill.

In denying that the Senator was entitled to orders requiring that members of the Commission hearing the matter should be bilingual, the Commission said it had made every effort to facilitate his wish to conduct his side of the hearing in Irish but there was no constitutional right to a bilingual court or tribunal for citizens who choose to conduct their business in Irish.

Mr Ó Domhnaill had from August 2011 until last March, when he changed solicitors, engaged with and addressed matters related to the expenses issue in English, it also claimed.

Giving the appeal court’s judgment, delivered in Irish, Mr Justice Peter Charleton, with whom Mr Justice Peter Kelly and Mr Justice Colm MacEochaidh agreed, disagreed the complaint was anonymous and found the substantive complaint before the Commission was one made by the Mayor and County Manager of Donegal Co Council.

The court rejected further arguments that the Constitution or the law requires that the Commission members hearing the complaint should be bilingual.

Costs issues will be dealt with in October.