Fianna Fáil leader Micheál Martin said "very comprehensive due diligence" was done on presidential candidate Jim Gavin, but that an issue with a former tenant was "probably buried somewhere in the recesses of his mind".
The Irish Independent on Saturday reported that Mr Gavin owed a former tenant €3,300, an issue that culminated with his withdrawal from the Presidential Election.
Speaking on RTÉ's Six One News, the Taoiseach said Mr Gavin was "repeatedly asked" by the party if he ever had an issue with a tenant, which Mr Gavin had said: "Absolutely not."
Mr Martin said: "That was put to him because it emerged that he had rented out an apartment at one time in his life.
"I mean, there's only so much anyone can do in situations like this.
"I think what happened here, there was an issue happened in his life back in and around 2009.
"He clearly did not deal with it at that time or since, and probably buried it somewhere in the recesses of his mind and didn't deal with it and the consequences of that have now come home."
Watch: 'Very comprehensive due diligence' done on Gavin - Martin
Mr Martin said he accepted that many members of Fianna Fáil were hurting due to Mr Gavin's decision.
"Absolutely I take responsibility for that. I want to acknowledge that many, many members of the party are hurting out there today because of what has transpired.
"I fully accept that, and we've been through tough times in the past. I've been through tough times as leader of the party.
"This is a tough day for us as a party. It's not something I anticipated or wanted in any shape or form," Mr Martin said.
Gavin tenant issue was not disclosed to FF, says Chambers
Earlier, Director of Elections Jack Chambers said the issue between Mr Gavin and the tenant was not disclosed to the party by the candidate.
He said that Mr Gavin made the correct decision to leave the presidential race.
Last night, Mr Gavin announced he was withdrawing from the election "with immediate effect", after recent days had given him "cause to reflect".
In a statement, Mr Gavin said he "made a mistake that was not in keeping with my character and the standards I set myself" and that he was "now taking steps to address the matter".
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He added: "I have also thought long and hard about the potential impact of the ongoing campaign on the wellbeing of my family and friends.
"Taking all these considerations on board, I have decided to withdraw from the presidential election contest with immediate effect and return to the arms of my family."
Speaking on RTÉ's Morning Ireland, Mr Chambers stated that just a few days ago Mr Gavin said he had no record or recollection of a tenant who sought a rent refund of €3,300 16 years ago.
But on Saturday, the tenant contacted Fianna Fáil and said that they did have records to prove this, Mr Chambers said.
"I think Jim Gavin made the right decision. He was campaigning to become Uachtaráin Na hÉireann and he's right in saying that he does not want to bring controversy onto this office."
Mr Chambers explained that on Thursday, a press query was made to the party, and that was answered on Friday following engagement with Mr Gavin.
"At that time, he said he had no record or recollection of the particular issue that was set out in the article on Saturday. Subsequently, on Saturday, the tenant in question contacted the party and said that they did have records relating to this particular issue.
"And that was contrary to what the party had been told and what had been said on Friday.
"And it was clear that that was emerging as a very serious issue. That was put to Jim and obviously there was engagement with him.
"And then over the weekend it was clear that there was absolutely veracity to what the tenant had said. And Jim then retrieved partial records, which confirmed that this was an issue.
"And obviously the contradiction between what was said on Friday and what emerged reflects the seriousness of this."
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'Serious miscalculation’
MEP Billy Kelleher, who himself had sought be the party's candidate warned that the episode cannot be swept under the carpet.
He added it was a serious miscalculation, and it cannot just be swept under the carpet, Mr Kelleher said, and decisions that were made must have consequences.
"A lot of people are very upset over this across the country," Mr Kelleher said, adding it will badly impact the morale of the party.
The message from his colleague Barry Andrews is that the party leader now has to show humility over what he termed a "fiasco" for Fianna Fáil.
Fianna Fáil’s Dublin MEP added he does not believe there is a leadership issue to address following Mr Gavin's withdrawal.
The party is in good health but the process to select Mr Gavin was wrong, he said, and it needs to be examined, adding that he had sympathy for Mr Gavin and his family.
Ministers ‘frog marched out’
Fianna Fáil TD Pádraig O’Sullivan said Mr Gavin dropping out of the Presidential Election is "embarrassing" for the party.
The Cork North Central TD, who supported Mr Kelleher’s candidacy, said there needed to be "collective action" in the aftermath.
Speaking on RTÉ’s News At One, he said ministers were "frog marched out" to support Mr Gavin’s campaign to get the party’s nomination.
"I looked at it with disdain as I saw senior members of the party being frog marched out to declare support for a person that many of them hadn't even met or knew nothing about," he said
‘Any money owed must be paid back’
Minister for Children, Disability and Equality Norma Foley has said any money owed by Mr Gavin must be paid back.
Speaking on the same programme, Ms Foley said: "If money is owed, it must be paid back, there's absolutely no question about that."
She added: "I'd be equally clear in saying I do think the right decision has been made.
"I think it was the correct thing to do at this point to withdraw, to stand aside, notwithstanding that it’s really difficult for Fianna Fáil membership, given that we don't now have a candidate contesting the Presidential Election."
Ms Foley rejected accusations that senior party figures were "frog marched out" to support Mr Gavin.
"This wasn't a process that was invented, you know, two or three weeks before the selection of the presidential candidate.
"This was a process that has been in place for a considerable amount of time," the minister said.
Ms Foley added: "It wasn't done a month or two months, indeed even a year beforehand. We were all well aware of what the process was."
Withdrawal decision 'the correct one'
Last night, Mr Martin said he fully understands Mr Gavin's decision and believes "it is the correct one".
The Fianna Fáil leader said: "Jim has accepted that he made an error in relation to an issue that has arisen in recent days.
"He himself has said the office of Uachtarán na hÉireann is the highest in the land and the pinnacle of public service.
"He is clear that he does not want to bring controversy onto this office.
"This has been a very difficult decision for Jim given his commitment to public service."
Presidential candidates Catherine Connolly and Heather Humphreys both wished Mr Gavin well following his decision to withdraw.
Ms Connolly said: "Anyone who seeks to make Ireland a better place through public service should be commended.
"Jim Gavin has made the right decision for himself and his family. I wish him well."
Ms Humphreys said: "Jim Gavin has made an enormous contribution to our country. He served in the Defence Forces with distinction and his achievements and the groundbreaking changes he pioneered in Gaelic Football are a legacy which will stand the test of time for all those who love our national games.
"While I know this must have been a very difficult decision, it is clearly one Jim has made with the best interests of his family at heart.
"That is something all of us can relate to. I want to wish Jim and his family all the very best for the future."
Read more:
Fianna Fáil in crisis with Jim Gavin's withdrawal from presidential race
Watch: Jim Gavin questioned on tenant issue during presidential debate
Jim Gavin's statement in full
"When I announced my intention to contest the presidential election I did so in a spirit of lifelong public service and a love of country. That has always been my sole motivation.
I believe deeply in this country, its dreams, its hopes and above all its people. The office of Uachtarán na hÉireann is the highest in the land and the pinnacle of public service. It is an office that must be untainted by controversy or distraction.
I always knew the campaign would be robust and challenging and anyone who knows me knows that I have never shirked from a contest. I have always sought to act in honour and good faith.
However recent days have given me cause to reflect.
I made a mistake that was not in keeping with my character and the standards I set myself. I am now taking steps to address the matter.
I have also thought long and hard about the potential impact of the ongoing campaign on the wellbeing of my family and friends.
Taking all these considerations on board, I have decided to withdraw from the presidential election contest with immediate effect and return to the arms of my family.
Throughout this campaign I have been humbled by the encouragement and kind words I received. So many people have gone out of their way to support me in so many ways, and I would like to express my sincere thanks to them. I truly hope you understand my decision and do not feel let down.
Go raibh míle maith agaibh."
Additional reporting PA, Mícheál Lehane
