Watch: McDonald defends handling of Sinn Féin issues

Sinn Féin leader Mary Lou McDonald has described the behaviour of former Senator and party member Niall Ó Donnghaile as "completely unacceptable" and that Sinn Fein did "all things that were necessary" to send information to the relevant authorities to hold him to account for his behaviour.

Speaking on RTÉ's Six One, said she wished Mr Ó Donnghaile well when he resigned in December last year because it was the right thing to do at the time as he was in a "mental health crisis".

She said she was fearful what a "public articulation" of the situation would do to him.

Ms McDonald was speaking after it was revealed by Niall Ó Donnghaile that he is the person who sent messages to a 17-year-old male party member.

Pressed on the statement she made after his resignation last year, Ms McDonald defended her comments;

"When I said on his leaving that I wished him well in dealing with his health I meant that and to this day I mean that and I wish his family well"

"A person's mental health particularly in extreme, matters all the time, including when they have done something wrong, including when they have behaved really, really badly and he had behaved really, really badly".

She said the sanction against Mr Ó Donnghaile which included resigning his position in the Seanad and leaving the Sinn Fein party "was a lot and it was the right thing, it was appropriate"

Ms McDonald said Sinn Fein did not make the Belfast GAA club, Laochra Loch Lao, where Niall Ó Donnghaile was honorary president, aware of the complaint because she said it wasn't something a political party would do.

She said once a referral was made to the police and the social services it was up to those agencies to determine a safeguarding assessment after their joint investigation.

Laochra Loch Lao confirmed earlier today that Mr Ó Donnghaile had resigned from the club.

She said Sinn Féin's job was to refer onwards to the appropriate agencies and that the party had "robust processes that they are applied efficiently".

She reiterated comments that she made in the Dáil, that the complaint made against former Sinn Féin TD Brian Stanley was serious and that the complainant feels "traumatised and distressed."

Ms McDonald said that in the course of the inquiry into that complaint, when Mr Stanley made "a counter allegation which was very serious".

"At that point Deputy Stanley was advised to go to the gardaí and he didn't," Ms McDonald said.

"That is something he will have to explain himself," Mr McDonald said.

When asked why the Party didn't refer the matter to gardaí sooner, Ms McDonald said: "Probably to the letter of things it would be for Deputy Stanley to go to the gardaí or for the complainant to make a referral, but as a political party here we are."

Ms McDonald reiterated that the party referred the complaints to gardaí out of what she said was "an abundance of caution" over the weekend after the party's preliminary concluded, more legal was taken and she and the party chair were briefed.

"We decide to refer everything on to the gardaí because it would not have sat comfortably with me and I don't think it would have been right or acceptable top have a complaint on the one hand and counter allegation with Sinn Fein and nowhere for a resolution or a conclusion, so I think the right thing was to refer those matters on".

Ms McDonald confirmed that the referral was lodged with Kevin Street Garda Station on Sunday.

The Sinn Féin leader cautioned against drawing conclusions about the timing of the complaint on the very first day of a 10-day nomination period for potential party general election candidates for Laois.

"I'm not going to attribute motive to anybody, all I know is when a complaint is made, and especially a serious one, and especially in relation to one of our elected members, I don't ascribe motive , I take it and the party takes it and then the process is run without fear or favour, independently and fully," Ms McDonald said.