Social Democrats co-leader Catherine Murphy is yet to give evidence to the commission investigating the sale of Siteserv to Denis O'Brien, despite four days being put aside for her appearance last month.
It is understood the commission of inquiry, chaired by Mr Justice Brian Cregan, had invited Ms Murphy to come before it on February 26th.
The Kildare North TD had initially not been included on a list of witnesses scheduled to come before the commission, but in January it emerged that she had been invited and had indicated she was willing to appear.
However, sources said that since then, differences of opinion have emerged over the manner in which cross-examination may be undertaken and around the naming of sources.
It is not known now whether Ms Murphy will appear in the future, or whether the commission will attempt to compel her to come before it.
Ms Murphy’s claims in relation to the sale of Siteserv, which she made under Dáil privilege, were central to the decision to set up the commission.
Mr O’Brien purchased Siteserv through his company Millington for €45 million in 2012. IBRC had previously given Siteserv a loan write down of €110 million.
Decision upheld
The Supreme Court last week upheld a High Court decision that Mr O’Brien’s privacy was not breached by statements made by Ms Murphy and Sinn Féin TD Pearse Doherty during a Dáil debate in 2015 about the sale of Siteserv.
The commission was established by then taoiseach Enda Kenny in 2015 to investigate all disposals by IBRC, the former Anglo Irish Bank which resulted in a capital loss to the State-owned bank of more than €10 million.
The commission, which has cost €7 million to date, originally faced a deadline of December 31st, 2015 to complete its report, but it quickly became apparent that it would not complete its work by then.
Taoiseach Leo Varadkar told the Dáil earler this year the final price tag for the inquiry is now expected to top €30 million, which was labelled “extraordinary” by Fianna Fáil leader Micheál Martin.
Mr Varadkar met opposition politicians before Christmas as he considered the inquiry’s request to extend its deadline by another 15 months. He was said to be considering scrapping the inquiry altogether, but eventually decided to grant the commission a reprieve.
He ultimately asked Mr Justice Cregan to submit a further interim report by the end of this month, detailing interim findings or conclusions, options to reduce the timeframe or cost of the inquiry, and its best estimates of the final costs of the first module, which is focused on the sale of Siteserv.
Spokespersons for the commission and for Ms Murphy had no comment on her failure to appear.
