The former Supreme Court judge, Mr Hugh O'Flaherty, is believed to be seeking clarifications about privilege before he agrees to answer questions from an Oireachtas committee next week.
In a separate development in the continuing Philip Sheedy controversy, former Dublin Fianna Fail councillor Mr Joe Burke has confirmed he provided a character reference for Sheedy's court proceedings.
But he added he had "no other connection or involvement, direct or indirect, deliberate or unintended", in the way the case was processed. And in a statement responding to weekend newspaper reports, he also said: "I never mentioned the matter directly or indirectly to anyone in the judicial or political domain."
Mr O'Flaherty is expected to write to the Committee on Justice, Equality and Women's Rights today or tomorrow clarifying certain aspects of the May 6th hearings - to which he, with the former High Court judge, Mr Cyril Kelly, and the former Dublin County Registrar, Mr Michael Quinlan, have been invited.
It is believed his questions centre on privilege. While committee members have absolute privilege in what they say, witnesses called before them do not enjoy such immunity, and Mr O'Flaherty, Mr Kelly and Mr Quinlan were told so last Friday.
Precedent exists whereby witnesses before Oireachtas committees can be given special privilege: legislation was enacted to allow the then Attorney General, Mr Eoghan Fitzsimons, to testify with immunity in the hearings about the events which led to the 1994 collapse of the Fianna Fail-Labour government.
None of the three witnesses has yet indicated whether they intend to accept the invitation, but sources close to Mr O'Flaherty say he is anxious to attend.
Meanwhile, Mr Eoin Ryan's chairmanship of the committee developed into a party political row yesterday after he indicated he would vacate the chair in favour of Fine Gael's Ms Monica Barnes if and when Mr Cyril Kelly gave evidence.
Fine Gael's justice spokesman, Mr Jim Higgins, said Mr Ryan was doing the "right thing" in the light of his acknowledged acquaintance with Mr Kelly's wife, Ms Patricia McNamara. Ms McNamara has been a leading figure in the Fianna Fail organisation in Dublin South East, Mr Ryan's constituency.
But Labour's justice spokesman, Mr Brendan Howlin, said that given the "possible links" between the different figures involved, it was impossible to see how Mr Ryan could avoid a conflict of interest by only temporarily vacating the chair.
This in turn was rejected as "a cheap shot" and "cowardly" by Mr Ryan.
Last night, a former Fine Gael minister for justice, Mr Jim Mitchell, predicted Mr Ryan would have great difficulty satisfying the principle of "objective bias", as established by the Supreme Court in a case concerning Miss Justice Mella Carroll.
Mr Mitchell, chairman of the Committee of Public Accounts, warned if Mr Ryan insisted on chairing hearings not involving Mr Kelly, he could leave the committee open to later challenges.
Comments in court yesterday by Judge Joseph Mathews, the sentencing judge in the Sheedy case, pointed to the possibility of him too attending the committee hearings.
Granting Sheedy an extension of time in which to appeal, he referred to "substantial collateral matters" in the case which should be dealt with "in the appropriate forum".
