RTÉ’s director general, Noel Curran, has also vowed to restore the station’s good name for investigative journalism.
Mr Curran, whose offer of resignation over the scandal was turned down by the RTÉ board, made his comments in an article he wrote for a Sunday newspaper in which he again apologised for the wrong done to Fr Reynolds, and set out how RTÉ is responding.
He said few media organisations can thrive without their public’s faith.
“For a publicly owned media service, that bond is fundamental,” he said.
Mr Curran defended the “proud record” of Prime Time Investigates which, over 54 programmes broadcast since 2003, has shone “a beam into dark corners and facilitated national debate”.
But he insisted that RTÉ understands the shock and hurt felt around the country by the treatment of Fr Reynolds in its Mission To Prey programme last May.
He said a lot of work is being done behind the scenes to compile a detailed account of what occurred in the lead-up to the broadcast of the programme.
He said RTÉ may appear to have been slow to react, but that it is not only examining how the libel came to be broadcast, but is stress-testing all of its editorial processes.
He said RTÉ will co-operate fully with the Broadcasting Authority of Ireland’s (BAI) inquiry, ordered by communications minister Pat Rabbitte.
He said RTÉ’s own investigations should be completed within three weeks, and the BAI inquiry completed in two months.
“It is an absolute requirement that the account given and the measures outlined be such as to renew and restore the public trust that is our bedrock, our lifeblood, and our currency,” said Mr Curran.
“I give my guarantee that this will be done. The Irish public deserves nothing less.
“I am deeply sorry that we have disappointed our licence fee payers, who rightly expect the highest standards from RTÉ.”
But he said: “We cannot lose our nerve when it comes to pioneering journalism — it is too important for our society.
“Investigative journalism, trusted and fully resourced as a fixture in our schedules, will resume, with our full commitment to it as a key priority and a core service to the Irish public.”
Meanwhile, Tom Savage, chairman of the RTÉ Authority, has said the crisis has “rocked the organisation to its foundations”.
The libel, which forced RTÉ to pay out an undisclosed six-figure sum to Fr Reynolds, has resulted in Ed Mulhall, the director of news and current affairs, and Ken O’Shea, the editor of Prime Time Investigates, stepping aside pending the outcome of the investigations.
Brian Pairceir, executive producer, and Aoife Kavanagh, who reported on the programme, will no longer be involved in on-air programming while the probes continue. The series has been taken off the air.