Fianna Fáil justice spokesman Niall Collins has accused Alan Shatter of misleading the Dáil in relation to bugging claims at the offices of the Garda Ombudsman Commission.
Deputy Collins said the Justice Minister was informed on Monday by Ombudsman Simon O'Brien that they had begun a "public interest" investigation focused on An Garda Síochána and that the same report was given to the Public Service Oversight Committee last Wednesday.
The news comes on the back of revelations in the Sunday Times today that a security sweep at GSOC was carried out after it emerged that a senior Garda appeared to have information about a case being investigated by the office.
On Tuesday evening, Minister Shatter dismissed as "completely baseless innuendo" any suggestion that the Garda Síochána was behind the alleged bugging of the force’s official watchdog.
"Alan Shatter completely misled the Dáil last Tuesday night; there's no doubt about it," said Deputy Collins. "He was in possession of both a written and an oral briefing from Simon O'Brien.
"It was confirmed to us in the committee on Wednesday evening that the Ombudsman Simon O'Brien fully informed Alan Shatter as Justice Minister that he had opened a public interest investigation and that investigation was focused on An Garda Síochána.
"That is hugely, hugely important."
Mr Shatter has agreed to appear before the Oireachtas Oversight Committee on Wednesday. Its chairman Sinn Féin’s Padraig MacLochlainn has said the Justice Minister has questions to answer over his accounts of the controversy.