A member of the Oireachtas Justice Committee says Brian Purcell should take the opportunity today to clarify all the issues surrounding the departure of Garda Commissioner Martin Callinan.

The Secretary-General at the Department of Justice will appear before the committee later but says he will not answer questions about the matters which fall under the remit of the Fennelly Inquiry.

That includes illegal recordings at garda stations and events leading to Commissioner Callinan stepping down.

The justice spokesman for Fianna Fail, Deputy Niall Collins, told Newstalk Breakfast that he does not understand the problem.

The Taoiseach has previously said he himself has not been asked to go before TDs to explain the resignation of Martin Callinan.

But Enda Kenny said that it was up to the Oireachtas Committee to decide if it wants to question him over the events that led to the former Garda Commissioner stepping down.

Mr. Kenny said he will be called before the Fennelly Inquiry - which will be investigating the garda tapes affair and the events that led Mr. Callinan to quit.