Justice Minister Alan Shatter has piled huge pressure on the chairman of the Garda watchdog by twice failing to express confidence in him.
In a fresh twist to the week-long bugging saga, Mr Shatter suggested that the chairman of the Garda Siochana Ombudsman Commission (GSOC), Simon O'Brien, provided "confused and contradictory" accounts of the controversy.
He also implied Mr O'Brien had given a different version of events to him than that delivered to an Oireachtas committee just days later.
Mr O'Brien's position looks increasingly untenable after the Justice Minister failed to express confidence in him, skirting the issue twice on RTE's 'Prime Time' programme last night.
While he said he retained confidence in GSOC, the relationship has been rocked by the fallout from revelations that the watchdog's offices may have been subject to some sort of surveillance.
The controversy began with revelations in a Sunday newspaper about the suspected bugging of the GSOC offices – which Mr Shatter knew nothing about.
The Justice Minister admitted he is "being accused by political opponents of misleading the Dail", because on Tuesday he had told fellow TDs there was no evidence of such unauthorised surveillance.
But the following day, GSOC chairman Mr O'Brien told the Oireachtas Public Service and Oversight Commission that he suspected surveillance had taken place.
Mr Shatter last night revealed his own statement to the Dail was based on a two-hour meeting with Mr O'Brien and two officials on Monday.
Mr Shatter was told that GSOC did not rule out that there could be "reasonable explanations" for the three technical anomalies it found in its investigation, and there was "no definitive evidence" of unauthorised surveillance.
And GSOC's written report to the minister, seen by the Irish Independent, merely states that the anomalies "raised concerns" about the integrity of its security.
A written briefing was provided afterwards, while Mr Shatter also cited a press release issued by GSOC itself.
"When this issue arose I invited Simon O'Brien to brief me fully on these events. He spent two hours with me in my office," Mr Shatter said.
"The information I gave the Dail in the statement that I delivered on Tuesday evening was based entirely on the oral briefing received from the chairman of GSOC, the written briefing, and on their press release.
"In the context of that, the conclusion was that there was no definitive evidence of any unauthorised technical or other surveillance of GSOC." He added: "At no stage during his oral briefing, the context of the written brief or indeed the press release GSOC issued, was it stated that he or members of GSOC believe they were under surveillance."
But Mr O'Brien went on to tell the Oireachtas committee that threats identified were on the "higher level of suspicion" and he did suspect bugging had taken place.
Mr Shatter was last night asked whether he thought he had been given a different story to that outlined at the committee.
He said: "I am very conscious that Mr O'Brien and the other members of GSOC were at a committee meeting for up to four hours and series of questions were put to them.
"I think during the course of that event there were different answers given with regard to particular issues. Some of what was said during the course of that seemed to me to be a little confused or contradictory."
Mr Shatter added: "I do think there is some confusion arising from the four hours of hearings that took place. My objective and my only objective was to tell the Dail the truth of what I knew about these matters.
"What I knew about these matters was based on the briefing I got from the chairman of GSOC, and also from the written submission they made to me."
He said: "My concern regarding this matter has resulted in me writing to GSOC requesting that these matters be clarified."
He also notably failed to express confidence in Mr O'Brien by name when asked to do so.
"I have confidence in GSOC," said Mr Shatter.
There was no formal comment from GSOC last night, but a spokesperson said Mr O'Brien is expected to respond to Mr Shatter today.
Earlier Tanaise Eamon Gilmore insisted that Mr O'Brien should have told Mr Shatter of his suspicions about alleged surveillance late last year.
The Labour leader emphatically replied: "Am I satisfied that no organ of State put the Garda Ombudsman's office under surveillance? Yes I am."
Earlier, five TDs and two senators estranged from the Fine Gael party last night launched a fierce attack on the Government's handling of the Garda Ombudsman controversy.
The seven members, regrouped as the Reform Alliance, accused the Government of "undermining" the ombudsman and failing to address the lack of trust between it and the gardai.
"A judicial inquiry needs to be established to investigate all of the events which brought about such high levels of mistrust between GSOC and An Garda Siochana," they urged.