A portrait of former Sinn Fein Belfast Lord Mayor Niall O Donnghaile has been removed from City Hall amid a controversy around text messages he sent to a teenager.

Group leaders on the council agreed to the move on Thursday following Mr O Donnghaile’s admission he quit Sinn Fein last year after the party received complaints over him sending allegedly inappropriate texts to a teenage party member.

Sinn Fein referred the matter to the PSNI and social services last September, but no criminal investigation was undertaken.

Sinn Fein vice president Michelle O’Neill said the removal of the portrait was “appropriate” given what she described as Mr O’Donnghaile’s “completely inappropriate” behaviour.

Mr O Donnghaile became the youngest Lord Mayor of Belfast in 2011 and, like all who hold that office, had an official portrait painted and displayed to mark his year in the role.

He went on to serve as an Irish senator before his resignation last December.

Sinn Fein is facing questions over its handling of the case, which emerged after the separate case of the former party press officer, Michael McMonagle, who admitted child sex offences earlier this year.

McMonagle, 42, from Limewood Street, Londonderry, last month admitted to a series of offences, including attempting to incite a child to engage in sexual activity.

Sinn Fein backed the call to remove Mr O Donnghaile’s portrait from City Hall.

Asked about the proposed removal when speaking to reporters in Belfast on Thursday morning, First Minister Ms O’Neill said: “I think it is appropriate. His behaviour was completely inappropriate so, therefore, I think that we had no issue whatsoever in backing the removal of the portrait.”

Asked whether she had any regrets over her party leader Mary Lou McDonald issuing a statement paying tribute to Mr O Donnghaile’s contribution when he left in December, Ms O’Neill said: “I think Mary-Lou McDonald tried to set that record straight in terms of the considerations that she had to take on board, particularly in relation to his severe mental health, and that was the only consideration that we had whenever he stepped back.

“It’s appropriate that he stepped back but I’m very confident in terms of how we conducted ourselves, how we referred him to the PSNI and to social services, that that was correct and proper.

“I think that was appropriate but we were concerned about his mental health and we also had the issue of legally being able to name him.”

In a statement, Belfast City Council said: “After agreement at a meeting of the Party Group leaders today (Thursday 17 October), the portrait of former Lord Mayor Niall O Donnghaile has been removed from display at City Hall.”