The top civil servant at the Department of Justice will be questioned today on allegations that the department mishandled complaints of Garda malpractice.
Secretary General Brian Purcell will take questions from the all-party Oireachtas Committee on Justice about the findings of the Guerin report - and may also be questioned about the events which led to the resignation of Martin Callinan as Garda Commissioner.
The Guerin report criticised the lack of a paper trail in the Department of Justice in how it handled Garda complaints - and wondered, at some levels, whether the department fully realised its responsibility to investigate.
However Mr Purcell says he won't answer questions about the matters which fall under the remit of the Fennelly Inquiry.
That includes widespread illegal taping at Garda stations - and also the circumstances under which the Garda Commissioner, Martin Callinan, stepped down.
But committee members have made it clear that they'll ask any questions relating to their job - to scrutinise the justice system and the workings of the department.
Fianna Fáil's Justice spokesman Deputy Niall Collins says he does not understand the problem.
"Mr. Purcell is maintaining a position that he effectively has to disengage from that type of questioning because of the Fennelly Commission - but that just doesn't wash for me," he said.
"I just don't understand how coming into our Committee today and telling it as it is - I don't see how that compromises anything which Fennelly can do."
Mr Purcell's appearance before the committee is likely to put further pressure on the new Justice Minister Frances Fitzgerald to state whether or not she has confidence in the Secretary General.