Billionaire Denis O'Brien has paid a €420,000 settlement to the Houses of the Oireachtas to cover the costs of legal fees after the organisation defended itself against an action taken by the businessman.

The costs relate to Mr O'Brien's failed action against the body over statements made about his banking affairs in the Dáil in 2015 by Sinn Féin finance spokesman Pearse Doherty and co-leader of the Social Democrats Catherine Murphy.

He took the legal action when an Oireachtas committee decided not to censure the two deputies for disclosing details of Mr O'Brien's finances under parliamentary privilege in the Dáil.

A breakdown of the legal costs paid by Mr O'Brien last year were released in a Freedom of Information request to Catherine Murphy this week.

They show that total costs paid by the businessman inclusive of VAT were made up of solicitor fees of €178,855, payment to senior counsel Michael Collins of €79,950, senior counsel Sara Moorhead was paid €92,250, barrister David Fennelly received €61,500 and there was an additional outlay of €7,444.

The payments to the Houses of the Oireachtas only relate to its costs and do not include the cost of Mr O'Brien's legal representation.

The issue originally related to a story that RTÉ proposed publishing in 2015 about Denis O'Brien's borrowings from IBRC, formerly Anglo Irish Bank.

Mr O'Brien had looked for more time to pay off his loans in 2013.

He owed the State-owned bank €320m having already repaid €525m of his borrowings.

He went to the High Court and secured an injunction to prevent RTÉ from publishing the story in April 2015, which would have revealed his borrowings and his request for more time to pay off his loans.

However, in the Dáil the following month Pearse Doherty and Catherine Murphy read out similar information to the material that RTÉ had tried to broadcast.

The Houses of the Oireachtas have parliamentary privilege, which means politicians cannot be sued for statements they make in the Dáil or Seanad.

However, the information disclosed by the two TDs was already the subject of a High Court injunction.

Details of Mr O'Brien’s banking affairs were then reported in the media.

The businessman complained to the Oireachtas Committee on Procedure and Privileges.

It found the TDs had not breached relevant rules by discussing matters that were before the courts.

Mr O’Brien then brought the matter to the High Court, arguing the committee’s finding was based on an error in interpreting a Dáil standing order.

The High Court ruled the courts could not intervene in statements made in the Dáil, nor how they were dealt with by the committee.

Mr O’Brien then appealed that judgment to the Supreme Court. It dismissed the appeal and Mr O'Brien had to pay the costs.

A spokesman for the businessman did not respond to a request for comment this week.

A spokeswoman for the Houses of the Oireachtas confirmed that the payment was made by Denis O'Brien in August 2021.