The long-running Government-ordered investigation into the sale of building services group Siteserv to a Denis O'Brien-owned company had cost almost €3.3 million by the end of February.
The bulk of the expenses incurred by the commission of investigation led by High Court judge Brian Cregan have been spent on lawyers' fees and salaries, wages and allowances, figures released by the Department of the Taoiseach under the Freedom of Information Act show.
Costs described as “incidental expenses”, comprising mostly legal fees, topped €1.5 million at the end of February, while salaries, wages and expenses had reached €646,000.
A further €1.06 million was spent on office expenses, equipment and supplies.
The investigation is examining the sale of Siteserv by the Irish Bank Resolution Corporation (IBRC), the State-owned bank made up of the remains of the defunct Anglo Irish Bank and Irish Nationwide Building Society, to O'Brien-controlled Millington in 2012 for €45.54 million.
The sale was followed by the write-off of a €110 million IBRC loan due from Siteserv.
The IBRC commission of investigation was established in June 2015 to investigate all transactions by the bank from January 2009 to February 2013 that involved a loss of more than €10 million to the State.
Taoiseach Leo Varadkar said last November the final cost of the commission would be between €20 million and €25 million, given the current rate of spending, the extended time frame for reporting, the risk of further delays and the significant third-party legal costs that will arise.
Former IBRC chief executive Mike Aynsley, a leading figure in the investigation, has said the commission could leave taxpayers with a bill of up to €100 million, a figure rejected by the commission.
The Department of the Taoiseach said the cost of the only other commission of investigation under its remit, the inquiry into the National Asset Management Agency's sale of its Northern Ireland loan portfolio known as Project Eagle in 2014, had cost €492,000 by the end of February.
The Moriarty tribunal, which found that former government minister Michael Lowry had "secured the winning" of the State's second mobile phone licence for Mr O'Brien's Esat Digifone consortium, had cost the State €62 million by the end of February, the department said.
The Mahon tribunal into planning corruption has cost the State €131.5 million by the end of February, according to figures from the Department of Housing, Planning and Local Government.
