Northern Ireland’s First Minister Michelle O’Neill has said she “fully accepts” that a young person sent inappropriate texts by former Sinn Fein senator Niall O Donnghaile was 16 years old when it occurred.

Ms O’Neill had told the Northern Ireland Assembly on Monday that party records had shown the teenager was 17 when the texts were sent.

She returned to the chamber on Tuesday to make an updated statement.

Sinn Fein has been battling with a number of controversies in recent weeks.

Sinn Fein’s president Mary Lou McDonald is expected to make an updated statement to the Dail on Tuesday (Brian Lawless/PA)

Last week Mr O Donnghaile acknowledged he quit Sinn Fein last year after the party received complaints that he had sent inappropriate texts to a teenage party member.

Sinn Fein has said it referred the matter to the PSNI and social services immediately last September, but no criminal investigation was pursued after police deemed that there had been no illegality.

Mr O’Donnghaile stepped down from the Seanad three months after Sinn Fein had referred the issue to the authorities.

Sinn Fein president Mary Lou McDonald last week told the Dail that the teenager was 17 when he had received the texts, a claim later repeated at the Stormont Assembly by Ms O’Neill.

However, the teenager told the Sunday Independent that he was 16 when he received what he described as “inappropriate messages” from Mr O Donnghaile last year.

Ms McDonald is expected to correct the record in the Dail on Tuesday.

Addressing MLAs at Stormont, Ms O’Neill said: “Yesterday I was asked about the age of the young person who was sent inappropriate text messages by a Sinn Fein representative. It was my understanding that the young person was 17 years of age based on the information of the application to join the party.

“This information was wrong. Over the weekend the young person made it clear that he was in fact 16 at the time and I fully accept this.

“This morning I want to put on the record that he was in fact 16 years of age when these inappropriate texts were sent.

“What happened to this young person was wrong. Niall O Donnghaile’s behaviour was unacceptable and entirely inappropriate and no young person should have experienced that.

“As I said yesterday, I am absolutely so sorry for the hurt caused by the statement issued following his resignation.”

Separately, Ms O’Neill also told the Assembly that a Sinn Fein member has resigned from the party after admitting involvement in damaging the portrait of a former DUP lord mayor at Belfast City Hall.

An investigation had been launched after the official portrait of Lord Wallace Browne was damaged at the weekend.

Ms O’Neill told MLAs: “Yesterday a Sinn Fein employee who worked in the Assembly made the party chief whip aware of their involvement in an incident regarding a portrait in Belfast City Hall.

“This took place on Saturday October 19. The employee was immediately suspended and we notified the PSNI.

“The employee has now resigned from their employment and their party membership.”

Lord Browne’s portrait was damaged just days after a portrait of Mr O Donnghaile, also a former Belfast lord mayor, was removed from the City Hall.