The Irish Council for Civil Liberties has called for an independent inquiry into the Garda Síochána Ombudsman Commission "bugging" controversy.
The independent human rights watchdog has said it cannot see the benefit of the Minister for Justice giving evidence to the Joint Committee on Public Service Oversight and Petitions on Wednesday.
ICCL Director Mark Kelly said Minister Alan Shatter has been very clear that all he has been doing is conveying the information he has been given by GSOC.
He said, in turn, GSOC has been clear that it has reached what it calls the limits of its technical capacity in terms of carrying out its investigation.
Speaking on RTÉ's Morning Ireland, Mr Kelly said the real issue is who bugged GSOC. He said an independent inquiry is necessary.
He said there are still questions to be answered and that it is important to get to the bottom of what really happened.
Yesterday, GSOC said that it wants to move on from the controversy.
Garda Commissioner Martin Callinan said again he was satisfied that gardaí were not involved in authorised or unauthorised surveillance of GSOC or its members.