Garda whistleblower Maurice McCabe is to retire from An Garda Síochána after 30 years’ service.

Sgt McCabe handed in his retirement notice over the weekend to Assistant Garda Commissioner Fintan Fanning.

His application will come into effect from midnight on Wednesday.

Garda Commissioner Drew Harris spoke to Sgt McCabe by telephone on the day the Disclosures Tribunal report was published. He has since met the whistleblower and apologised to him on behalf of the Garda.

Minister for Justice Charlie Flanagan also apologised to Sgt McCabe on behalf of the Government.

The tribunal found former Garda commissioner Martin Callinan and Supt David Taylor, former head of the Garda Press Office, had engaged in a “campaign of calumny” against Sgt McCabe.

This, the tribunal found, was done by the two men to denigrate Sgt McCabe in response to his whistleblowing.

On Wednesday Mr Flanagan said Sgt McCabe had left a “legacy” within the force, and had brought “serious failings” into the open. As a result the gardaí had been given “a huge opportunity to transform,” he said.

“I am very conscious that Sergeant McCabe and his family suffered greatly as a consequence of his courage. They have shown incredible resilience in appalling circumstances,” Mr Flanagan said. The Minister said he would be meeting Sgt McCabe in the “near future.”

Minister for Housing Eoghan Murphy said he was “surprised” to hear Sgt McCabe was retiring. Sgt McCabe had done Irish society a huge service, “to help reform the Garda Síochána itself, to ask difficult questions of those in power, and to shine a light into an area of Irish life that needed a light shone upon it,” he said.

Labour Party leader Brendan Howlin TD also paid tribute to Sgt McCabe, stating he had served the public with a commitment that “never wavered in the face of personal cost.”

Penalty points cancelled Sgt McCabe effectively became a household name in early 2014 when he appeared before the Public Accounts Committee (PAC) to give evidence in public about his whistleblowing.

He alleged corruption in how the points were cancelled, with no good reason in many cases and without some of the gardaí cancelling the points following proper procedures.

An internal Garda inquiry concluded while points were cancelled, corruption was not a factor.

It found almost five per cent of the 1.4 million penalty points issued between January 2009 and June 2012 had been cancelled.

Some 37,384 sets of points were cancelled by gardaí using “discretionary” powers.

However, neither the internal Garda investigation nor a later inquiry by the Garda Siochana Ombudsman Commission (Gsoc) could determine how many times points were cancelled without legitimate reasons.

Gsoc found that, in a force that had 14,000 members at one point, 442 gardaí cancelled penalty points.

Of the points cancelled, some were legitimate cancellations and the gardaí who cancelled them acted properly. However, it could not be determined how many were illegitimate cancellations.

In one case, a Dublin-based Garda member terminated 744 points incurred across 17 counties. He was disciplined with a fine of €3,000.

Devastating The Disclosures Tribunal, in its report published earlier this month, found that when the PAC was preparing to bring Sgt McCabe before it in 2014, that Mr Callinan and Supt Taylor had run a campaign of calumny against him aimed at denigrating him in response to his whistleblowing.

In a devastating finding, the tribunal said Mr Callinan told PAC chairman John McGuinness TD (FF) that Sgt McCabe had sexually abused Sgt McCabe’s own children and another person. Mr Callinan denied he said this.

None of these allegations about Sgt McCabe were true. He had never been accused of abusing his own children. However, a series of administrative errors within Tusla saw allegations made against somebody else attached in error to Sgt McCabe’s name.

Back in 2006, in a separate case, a young woman made an allegation of abuse against Sgt McCabe. However, this was investigated and dismissed by the DPP. The Garda investigation which resulted in a file being sent to the DPP recommended that Sgt McCabe should not be prosecuted.

It was in the period after this that Sgt McCabe, who was based in the Cavan-Monaghan Garda division, began his whistleblowing. He raised concerns about shortcomings in police work in the division and would also make allegations against named senior officers.

Some of the allegations about poor police work were found to be accurate by an internal Garda inquiry and others were not proven. The most serious allegations made against senior officers were not proven.

However, while Sgt McCabe began raising complaints just over a decade ago, it was not until he appeared before the PAC in 2014, when he was named for the first time and became a public figure, that his whistleblowing began having very significant impact.

‘Disgusting’ His appearance came during a time of intense controversy. At a meeting of the PAC just before Sgt McCabe appeared, Mr Callinan described as “disgusting” Sgt McCabe’s actions in downloading from Garda computers records of hundreds of cancelled penalty points.

And Mr Callinan also told the PAC he was against Sgt McCabe appearing before it, adding he planned to take legal advice on the invitation extended by PAC to Sgt McCabe.

The then minister for health and now Taoiseach, Leo Varadkar, said at the time he would call the whistleblowers’ actions “distinguished” rather than “disgusting”.

Mr Callinan never recovered from the controversy and while other matters also intervened - including the secret recordings of calls to Garda stations - he departed office in March 2014, after the Sgt McCabe controversy did most of the damage to his standing.

He was among a number of senior figures in the criminal justice sector who were effectively forced out of office under the pressure of the protracted controversies around Sgt McCabe’s allegations.

These included the ministers for justice Alan Shatter and Frances Fitzgerald, though both were exonerated by subsequent inquiries. Also departing office suddenly under pressure was the former Garda commissioner Nóirín O’Sullivan.

Ms O’Sullivan has also since been exonerated, like Ms Fitzgerald, by the findings of the tribunal.

The tribunal found Sgt McCabe had acted in the public interest and had done the State some service in raising the issues that he did.

He has been off sick from work for over two years and now that he is retiring a number of legal actions, including against the Garda, are expected to be pursued by Sgt McCabe.