The son of Sinn Féin assembly member Carál Ní Chuilín has denied being involved in damage to a portrait of a former Belfast lord mayor.

A solicitor for Naoise Ó Cuilín dismissed as “entirely false, baseless and malicious” the allegation related to the painting of Democratic Unionist Party (DUP) peer Lord Browne.

Mr Ó Cuilín, a former Sinn Féin staff member at Stormont, resigned following the incident at City Hall in October last year, which police investigated as a hate crime.

No prosecution is being pursued after the Public Prosecution Service (PPS) on Monday confirmed “key gaps remained” in available evidence.

The decision has prompted speculation in recent days over the identity of the former Sinn Féin employee.

At Stormont on Tuesday, it was claimed the person who “attacked” the portrait was the son of a Sinn Féin assembly member.

And earlier on Wednesday, a Northern Ireland Assembly committee heard claims Ní Chuilín’s son had been “named on social media as being involved in the damage”.

Mr Ó Cuilín’s solicitor Niall Murphy issued a statement on Wednesday evening on behalf of his client rejecting the allegation.

“For absolute clarity, and on our client’s behalf, I state unequivocally that our client did not cause any damage whatsoever to the portrait of Lord Wallace Browne,” he said.

“Any suggestion to the contrary is wholly unfounded.”

The painting was damaged following an event at City Hall to celebrate an Irish-language group.

It was attended by a number of high-profile Sinn Féin figures.

The PPS said issues in building a “clear evidential picture” included “no CCTV coverage”.

It also said the Sinn Féin employee’s resignation “contained no admission”, and a man interviewed by police “exercised his right not to answer questions”.

Mr Murphy said his client “responded positively” to a request by the Police Service of Northern Ireland (PSNI) to attend a voluntary interview “and was prepared to give an account”.

“However, the paucity of evidence against our client was such that I advised him that there was nothing requiring an account, and that he should therefore exercise his lawful right to silence,” he added.

Mr Ó Cuilín is a university graduate with “no criminal record, and has never previously been accused of any criminal offence,” the solicitor said.

“The attempts to malign our client’s character in the absence of any evidence are wholly unjustified,” the solicitor added.

“Our client has worked continuously in the youth and community sector, on multiple projects which focus on addressing division, hate and sectarianism.”

He added that Mr Ó Cuilín was “appalled by the false commentary directed at him, particularly given the clear position arising from the investigation”.

Earlier at a meeting of Stormont’s Executive Office committee, Mr Ó Cuilín was named by Traditional Unionist Voice (TUV) assembly member Timothy Gaston.

He asked if Ní Chuilín “wants to make a declaration of interest”, adding that it was “regarding her son has been named on social media as being involved in the damage of that portrait”.

In response, Ní Chuilín said: “I’ve nothing to declare, absolutely nothing to declare.”

She pointed to how members were at the committee to discuss redress measures for victims of institutional abuse.

“I am here to scrutinise in front of us today draft legislation affecting victims and survivors, and that’s what I’m here to do today, and I have no interest to declare at all on behalf of myself or anyone else,” she added.

The committee also heard from Sinn Féín assembly member Aisling Reilly, a junior minister in the Northern Ireland Executive.

There were tense exchanges as Reilly was asked about her attendance at the City Hall event last year.

DUP assembly member Phillip Brett said he understood Reilly was invited to the event as junior minister and the invitation included “an offer of four free tickets”.

“I want to know did the junior minister issue that ticket to the person responsible for attacking the portrait,” he told the committee.

Reilly did not confirm how she received an invite, but insisted she “did not attend the event as junior minister”.

“I attended as a gaeilgeoir (a person who speaks the Irish language) and a West Belfast MLA (Member of the Legislative Assembly),” she said.

“I came here today as junior minister to talk about a really important piece of legislation.”

The junior minister said that “to end on this I feel is extremely crass”.

Gaston told the committee he understood Ní Chuilín’s son had been working for Reilly as a “translator”.

When he asked if this was correct, Reilly described the questions as “continued badgering” and reiterated she did not attend the event in her ministerial capacity.