The cost of the inquiry which is investigating write-offs on loans at the former Anglo Irish Bank is set to exceed €30m. 

Taoiseach Leo Varadkar updated the Dáil on the new costs of the Commission of Investigation into Irish Bank Resolution Corporation (IBRC) - formerly Anglo Irish Bank. 

Speaking during Taoiseach's questions in the Dáil this afternoon, Mr Varadkar said: "The final cost of the commission could exceed €30m." 

These costs were labelled "extraordinary" by Fianna Fáil leader Mícheál Martin, who said it is "absurd" whereby we are now entering the fifth year of investigating a transaction that took three months.

The IBRC Commission of Investigation, led by Mr Justice Brian Cregan, was established in June 2015. 

The Taoiseach explained "the commission is required to investigate certain transactions, activities and management decisions at the IBRC in its first module and it is investigating the Siteserv transaction, which has been identified as a matter of significant public concern in Dáil Éireann." 

Some bespoke legislation was enacted by the Oireachtas in March 2016 to give a new legal basis to the commission's investigations.

The commission's terms of reference were also amended in 2016. 

He said the time-frame for the commission has been extended on a number of occasions. Last November the commission sought a further extension of its deadline until the end of March 2020.

This request sparked concern across Government and opposition benches about the level of progress achieved by the commission to date. 

Mr Varadkar said that it was agreed to request a further interim report from the commission with any further interim findings and conclusions which the commission can make, any options the commission believes would reduce the time-frame or the cost and production of a final report on the first module of investigation, and a likely final cost estimate. 

The Taoiseach said that from the time of its establishment until the end of 2018, the commission spent approximately €5m on direct costs including salaries, administration, overheads and its own legal costs. 

He said the commission has not provided any estimate of third party legal costs incurred to date but they are likely to be substantial. He added: "It would be prudent to assume the final cost of the commission could exceed €30m". 

Sinn Féin Finance Spokesperson Pearse Doherty asked for a breakdown of the €30m figure.

Labour leader Brendan Howlin said the whole idea of a commission of investigation was to make it quicker and more efficient but we have had five interim reports that "contain nothing of great substance". 

Mr Martin said the €30m cost is "extraordinary" and pointed out that we are now in the fifth year of investigating a transaction that took three months. He said: "by any definition that is absurd". 

Social Democrats co-leader Catherine Murphy said she was also concerned about the costs. 

The Taoiseach said that as this is an independent commission led by Mr Justice Cregan, "I don't know and can't know the answers to the questions that people are asking". 

He said he has extended the commission's time-frame until the end of March 2019 and requested a further interim report.

He has asked that the report will include "any interim findings or conclusions which the commission is in a position to make at this stage, any options which the commission believes would reduce the time-frame and cost for production and final report at the first module; the commission's view on the risks to competition of the first module of the investigation within the new requested time-frame of March 2020, and the commission's best estimate of the likely final costs in the first module".