A senior garda official has written a report for the attention of the Minister for Justice outlining "significant developments" relating to the treatment of garda whistleblower Sergeant Maurice McCabe.

RTÉ's This Week programme has learned that John Barrett, head of human resources with An Garda Síochána, has formally recorded a number of specific areas with the recommendation that they be brought to Minister Frances Fitzgerald's attention.

It is understood that Mr Barrett specifically drafted the report, and has asked that it be forwarded to the Minister under Section 41 of the Garda Síochána Act, which relates to any issue of such importance that it can be regarded as a "significant development" that might affect public confidence in the force, relate to garda accountability or any other matters.

Documents prepared under Section 41 cannot be shelved internally and must be sent directly to the Minister for Justice.

It is understood that Mr Barrett sent the report to Donal O'Cualáin, Deputy Garda Commissioner in charge of strategy and change management.

The Garda Press Office declined to comment on whether this report has yet been given to Ms Fitzgerald.

Mr Barrett is the force's official liaison with Sgt McCabe, and it is understood the report originated from meetings he had with Sgt McCabe shortly after the conclusion of the O'Higgins Inquiry into alleged malpractice in the force, which reported in May of this year.

One of the issues raised in his memorandum to the minister relates to the alleged meeting between then garda commissioner Martin Callinan and then Public Accounts Committee chairman John McGuinness in a Dublin hotel car park in 2014, prior to Sgt McCabe's attendance before the Dáil committee.

Mr McGuinness has claimed in the Dáil that Mr Callinan attempted to discredit Sgt McCabe by suggesting that Sgt McCabe "was not to be trusted".

Mr McGuinness said Mr Callinan provided no evidence to support this and that Mr McGuinness did not believe it, and he said that contrary to what Mr Callinan said to him at the meeting, that Sgt McCabe was entirely credible in his complaints.

Mr McGuinness told the Dáil that "every effort was made to make sure he [McCabe] did not attend the Public Accounts Committee" to discuss his concerns over how some gardaí were abusing the fixed notice penalty points system, at massive cost to the State.

Sgt McCabe's claims were later fully borne out by the Garda Inspectorate.

The second issue raised in Mr Barrett's report is the so-called 'Mullingar meeting', which relates to conflicting accounts of a meeting between Sgt McCabe and two senior gardaí in 2008, in which Sgt McCabe produced a tape recording which called into question the official account of statements attributed to him at that meeting, and which were later submitted into evidence at the O'Higgins Inquiry into Sgt McCabe's claims.

It has been reported that one version of this meeting was presented which purported to claim that Sgt McCabe said he was motivated by malice when making certain complaints.

However, a tape recording produced by Sgt McCabe from that meeting contradicted that account of the meeting.

Garda Commissioner Nóirín O'Sullivan has asked Ms Fitzgerald to forward this issue to the Garda Síochána Ombudsman Commission to investigate.