The final report of the Charleton tribunal is likely to be published in October, its chairman said yesterday at the end of its last sitting.

The tribunal, established by the Oireachtas in February 2017, sat in public and private for more than 100 days.

Mr Justice Peter Charleton was asked to investigate a number of matters including whether the then head of the Garda Press Office, Supt Dave Taylor, was ordered by the then Garda commissioner, Martin Callinan, to conduct a smear campaign against Garda whistleblower Sgt Maurice McCabe.

Supt Taylor claimed this was known at the time to the then deputy commissioner, Nóirín O’Sullivan. Both former commissioners have denied the claim.

The tribunal has also heard claims from witnesses that in December 2013 and January 2014 Mr Callinan made negative comments about Sgt McCabe. Mr Callinan has disputed their accounts.

During closing submissions, Shane Murphy SC, for the two former commissioners and Garda HQ, said the fact that five witnesses have separately said Mr Callinan made different negative comments to them about Sgt McCabe should not be seen as corroborating evidence for each disputed conversation.

Lacked ‘common sense’

However, Michael McDowell SC, for Sgt McCabe, said this lacked “common sense” and argued that the testimony of the five men about what were separate conversations should be assessed together.

The conversations took place at a time when the issue of penalty points was a public controversy due to claims made by Sgt McCabe.

Fianna Fáil TD John McGuinness and the Comptroller & Auditor General, Seamus McCarthy, said Mr Callinan referred to Sgt McCabe being linked to sexual offences. Mr McGuinness said he was told by Mr Callinan that Sgt McCabe was a “kiddie fiddler”.

Mr Murphy said that elements of the testimony given by Mr McGuinness were “implausible” and that his evidence was “unreliable”.

Referring to a submission made on Thursday by Supt Taylor’s counsel, Michael O’Higgins SC, Mr Murphy said that “as of yesterday no case is being made” against Ms O’Sullivan in relation to the smear campaign allegation and “a rather vestigial case” is being made against Mr Callinan.

Mr McDowell said his client was entitled to be “vindicated” by the tribunal as a man who has been truthful and well-motivated. Sgt McCabe was not at the tribunal as a “grand accuser” but as a witness whose name and reputation are “hugely at stake”.

He said there were “huge question marks” over aspects of Supt Taylor’s testimony that had been contested, but it was the case that evidence of a smear campaign had been presented to the tribunal.