Whistleblower Sergeant Maurice McCabe has rejected claims that the Garda Commissioner issued a directive for him to co-operate with the investigation into allegations that penalty points had been cancelled.

In a detailed statement seen by RTÉ’s Prime Time, Sgt McCabe said he found the suggestion he had been instructed to cooperate with the inquiry carried out by Assistant Commissioner John O'Mahony “gravely misleading and false”.

He said: “I was never directed by the Commissioner to cooperate with the O'Mahony investigation as alleged.”

Sgt McCabe based his statement on his own “full record” of a meeting on 14 December 2012 with a senior officer, Chief Superintendent Mark Curran, at Mullingar Garda Station.

Sgt McCabe said:“When he [Chief Superintendent Curran] arrived he read me out a document. I have, fortunately, a full record of what transpired and it is attached to this statement.

“As appears from the record, the Chief Superintendent refused my request to furnish me a copy of that document. I presume that this was in accordance with his superiors' instructions.

“The fact that I was denied a copy of the direction may have encouraged the author of the statement issued today about me to grossly misrepresent the terms of the Commissioner's direction as read out to me and as recorded by me.”

Sgt McCabe said the direction concerned his accessing the Garda PULSE system regarding the cancellation of fixed charge notices and that he should "desist" from doing so "and or disclosing to third parties sensitive personal data regarding the cancellation of fixed charge notices by members of An Garda Síochána."

Garda Commissioner Martin Callinan has said he wrote to Sgt McCabe 14 months ago and told him to cooperate with the inquiry.

Mr Callinan said he issued a direction to Sgt McCabe on 14 December 2012 to cooperate with the investigation being carried out by Assistant Commissioner O'Mahony and directing him to bring any information or concerns he had to the inquiry team.

The direction was delivered to him verbally by a senior officer, who Sgt McCabe has now stated was Chief Superintendent Curran.

It also directed him to bring any information or concerns he had to the inquiry team, which was led by Mr O'Mahony.

The Commissioner also told the Public Accounts Committee last month that "this gentleman (Sgt McCabe) has had ample opportunities to come forward with any complaints".

Members of An Garda Síochána are required to comply with directions issued by the Commissioner.

It is understood that Sgt McCabe may have been on sick leave for a number of months from December 2012  and did not contact the Assistant Commissioner until April of 2013, by which time the investigation had been completed.

Assistant Commissioner O'Mahony told the PAC that he was contacted on 13 April 2013 after he had forwarded his investigation report to the Minister for Justice.

The Assistant Commissioner said he asked the Sergeant if he had any information for him and offered to sit down with him and give him "a fair hearing".

Mr O'Mahony also told the committee that he did not engage (with Sgt McCabe) during the investigation because of the information he himself had from the Garda's PULSE computer system.

"I found what was on PULSE did not accurately reflect what they (the whistleblowers) were alleging," he said.

Senior ministers rally in support of Alan Shatter

Two senior Cabinet colleagues of Minister for Justice Alan Shatter have said he retains their full confidence.

Mr Shatter has been under pressure following the alleged bugging of the Garda Síochána Ombudsman Commission and the penalty points controversy.

Minister for Health James Reilly said Mr Shatter is one of the hardest working ministers and has been prodigious in the amount of legislation he has produced.

Mr Reilly said Mr Shatter is an individual bent on reform of his profession, as he has been in health.

Asked about whether there should be an independent inquiry or whether Sgt McCabe was owed an apology, Mr Reilly said there is a review in the Department of Justice and it would be premature to pre-empt it.

Elsewhere, Minister for Communications Pat Rabbitte said Mr Shatter is one of the best justice ministers he has seen in the last three decades.

He said Minister Shatter is "a reforming minister" and is "particularly diligent and attentive".

Mr Rabbitte said he was not in a position to draw conclusions on recent allegations and on whether Mr Shatter should apologise to Sgt McCabe.

Minister Rabbitte said he is expecting Mr Shatter to report to Cabinet tomorrow.

When asked if he was satisfied to wait until then, Minister Rabbitte said some of the allegations are "a number of years old" and waiting another day is not going to make any difference.

He said we need the right outcome, not a speedy outcome.

Opposition increase pressure on minister

Sinn Féin's Pádraig Mac Lochlainn confirmed he had spoken to a new garda whistleblower.

The party's justice spokesperson said he is awaiting documentation from the female garda, which will be forwarded to Taoiseach Enda Kenny.

Fianna Fáil leader Micheál Martin said the publication of the Garda Inspectorate report on the penalty points investigation led by the assistant commissioner would shed light on the entire approach to the saga and any failings that inquiry may have had.

Mr Martin said the Road Safety Authority wrote to Minister for Transport Leo Varadkar identifying failings of that inquiry at the time and it said the chief failing was the failure to interview Sgt McCabe.

Mr Martin was speaking on RTÉ's Today with Seán O'Rourke.

Read Mícheál Lehane's blog on the challenges facing Alan Shatter