The unit was set up to deal with information flowing from the force to the Disclosures Tribunal, and was staffed initially with retired members selected by former commissioner, Nóirín O’Sullivan.

Today the Irish Examiner has reported that a principal officer in the Department of Public Expenditure expressed concerns about re-employing retired officers to staff this unit.

The correspondence, obtained under the Freedom of Information Act, between officials of the departments of Public Expenditure and Justice raises some disturbing questions. Public Expenditure questioned whether re-employing retired officers might “impact negatively on the workings of the tribunal thereby compounding ongoing problems”.

This was written in the context of issues that “continue to surface and to impact on the public trust and confidence in An Garda Síochána”.

The official in Public Expenditure, principal officer John Burke, wanted to know if there was any other way in which the force could liaise with the tribunal.

These concerns were expressed in a letter dated April 12, 2017. By then, others were already raising questions as to whether the unit, staffed by retired members selected by then-commissioner Nóirín O’Sullivan, was an appropriate way to liaise with the tribunal.

What if a member of AGS wanted to meet with tribunal investigators on a confidential basis?

What if a member wanted to provide information that might not find favour with the then commissioner?

None of this is to suggest that the integrity of the members of the liaison unit could be called into question, but perception is a huge issue. If members were of the opinion that the retired men staffing the unit were close to Ms O’Sullivan, that would be enough in a closed organisation like AGS to desist from going any further.

A somewhat similar scenario pertained to the O’Higgins commission, which investigated Sgt Maurice McCabe’s complaints of malpractice. A representative of the commissioner was present for all the hearings. This meant the commissioner was effectively privy to all evidence tendered by members of the force.

The other issue was that the serving gardaí in apparent conflict with Ms O’Sullivan at the tribunal — Sgt McCabe and Supt David Taylor — had no trust in the unit to act neutrally. Again, this is no reflection on the members of the liaison unit but the fact that Ms O’Sullivan selected them, and that there were known to be professionally close to either her or her husband, fed the perception of bias.

These matters had been aired by the time a principal officer in the Department of Justice, Anne Barry, wrote to her opposite number in Public Expenditure to request sanction to re-hire the retired members.

On March 18, this newspaper published a report outlining the kind of concerns detailed above.

The tribunal had been informed on March 30 by counsel for Sgt McCabe and Supt Taylor respectively of their concerns about the liaison unit. Judge Charleton heard the submissions but made no further comment on the matter.

That information may have informed the concerns expressed by the principal officer in Public Expenditure, John Burke. Or he may indeed have harboured his own concerns about rehiring selected officers for this particular task. Whatever it was, he did note that the move could impact on the “public trust and confidence” in the force.

The reply he got was that an alternative — employing a solicitor’s firm — had been “floated within An Garda Síochána but was not put forward by the commissioner”. Ms Barry also pointed out that the cost of employing a firm would be much greater than that of rehiring former garda members, and it would take longer for a solicitor’s firm to get up to speed.

Having received this assurance from Justice about the strategy, Mr Burke sanctioned the finance on May 5, but his letter did underline for emphasis the following: “Given your department’s assessment that this overall approach is appropriate…”. As such he was emphasising that the responsibility for re-employing the retired members was with Justice, and not his department.

While the Department of Public Expenditure was satisfied to give the go-ahead, another individual continued to have concerns about how the unit was operating.

John Barrett, head of human resources in AGS, wrote five times to the head of legal affairs in the force last year about the operation of the liaison unit.

Asked about this at a Public Accounts Committee meeting on November 23 last, Mr Barrett replied: “I wrote a number of letters setting out my views and it goes beyond resourcing.”

He was constrained from further comment about the issue at the meeting due to repeated interventions from acting commissioner Donall Ó Cualáin, who said he was objecting to the questions.

Some days after that PAC meeting, Mr Ó Cualáin himself officially informed the minister for justice of concerns about the unit in what is known as a “Section 41” letter, which obliges the commissioner to tell the minister of any problem which it is felt the minister should be made aware of. So it would seem that some nine months after the unit was set up, and seven after it was officially sanctioned, management in the gardaí came to the conclusion that perhaps it wasn’t such a good idea.

The correspondence published in the Irish Examiner today does raise further questions about how closely the Department of Justice and gardaí operate.

At the PAC meeting in November, it was stated that then-secretary general for the department, Noel Waters, gave verbal sanction for the unit in late February some days after Ms O’Sullivan contacted him with the proposal.

The caution expressed by the official from the Department of Public Expenditure was nowhere to be seen. Not just that, but within days of the verbal approval, employment contracts were drawn up for the retired members. Sanction for those contracts would not be granted for over another two months, yet the Department of Justice saw nothing wrong in this course of action.

All the available evidence suggests that the department appears to have been willing to go along with whatever the commissioner wanted without exercising any due diligence of her proposal.

And now, the matter has been referred to the minister for justice, who might well ask why his own department had not raised a red flag when the proposal for the unit was first broached last February.