A Sinn Féin member has resigned from the party after admitting involvement in an incident during which the portrait of a former unionist Mayor was damaged at Belfast City Hall.

Belfast City Council launched an investigation on Monday into reports the portrait of former DUP councillor and MLA Wallace Browne was removed from the wall of the Great Hall and the glass within its frame was smashed on Saturday night.

Mr Browne – also known as Baron Browne of Belmont after he received a peerage in 2006 – also served as former High Sheriff of the city and as MLA for East Belfast from 2007 until 2011.

An event celebrating 20 years of west Belfast Irish language group Glór na Móna had been taking place at City Hall earlier that evening.

Sinn Féin has confirmed it suspended a party member in relation to the incident.

“Today a Sinn Féin employee, who works in the Assembly, made the party Chief Whip aware of their involvement in an incident regarding a portrait in Belfast City Hall which took place on Saturday October 19,” said a spokesperson.

“The employee was immediately suspended, and we have notified the PSNI today.

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

The PSNI has been contacted for comment.

It comes after the DUP called for a “full and robust investigation” into the incident.

“It has come to our attention that the portrait of former Belfast Lord Mayor, The Lord Browne of Belmont, was damaged on Saturday night after an event in the Great Hall,” said the party’s deputy group leader Dean McCullough.

“Following our initial request for an urgent update, it appears that a person or persons unknown removed the Lord Wallace Browne portrait from the wall and smashed the glass within the frame.

“One cannot but question, therefore, if this is in any way linked to the rightful removal of the portrait of former Belfast Lord Mayor, Niall Ó Donnghaile – following yet another Sinn Fein scandal.

A portrait of former Sinn Féin Lord Mayor Niall Ó Donnghaile was removed last week following revelations he sent inappropriate text messages to a 16-year-old boy

“Let us be clear, we will not tolerate the portraits of upstanding public servants, and Democratic Unionists, being damaged in our City Hall.”

Belfast City Council has confirmed an investigation into the incident is underway.

“The portrait of former Lord Mayor, Lord (Wallace) Browne of Belmont has been removed from public display after it was damaged over the weekend,” said a spokesperson.

“We are currently assessing the extent of the damage and looking into the circumstances which led to the portrait being damaged. No further action has been taken at this time.

“We hope to complete any necessary repairs as soon as possible so the portrait can be put back on display.”

A Glór na Móna spokesperson said they were unaware of the incident until contacted by council staff on Monday morning and that they are co-operating with the council’s investigation.

“On October 19 Glór na Móna held a celebratory dinner in City Hall to mark 20 years since the foundation of the organisation,” they said.

“Following the formal end of our event, a portrait within city hall was damaged. Glór na Móna had no knowledge of this taking place and only became aware of this on Monday October 21 when contacted by council staff.

“This is completely contrary to the ethos and principles of our organisation and the spirit of our successful anniversary celebratory event.

“We are extremely disappointed that this took place after what was an incredibly positive evening. We are assisting Belfast City Council with their investigation into the circumstances of this damage.”

It comes after former Sinn Féin Lord Mayor Niall Ó Donnghaile’s portrait was removed from the Great Hall last week following revelations he left the party after sending inappropriate text messages to a 16-year-old boy.

The portrait was removed after agreement between council parties, with Sinn Féin Vice President Michelle O’Neill saying the party had “no issue whatsoever” backing the move.

However a former councillor – Fergus O’Hare – this week branded the move “grossly unfair”, suggesting all former Mayors must now be assessed according to “agreed and transparent criteria and standards”.

News Catch Up: Monday 21st October