No further action is to be taken against Sinn Féin MLA Gerry Kelly over a tweet around a mass escape from the Maze Prison by IRA terrorists.
Justice Minister Naomi Long said the decision was taken following legal advice.
Mr Kelly has been accused of breaching the Northern Ireland Policing Board's Code of Conduct by "glorifying IRA terrorism" in September when he tweeted about the anniversary of a mass breakout from the Maze prison.
The North Belfast MLA was one of 38 republican prisoners who escaped from the Maze in 1983.
He described the breakout in his tweet as "one of Big Bob's best ops", referring to senior republican Bobby Storey, adding "I had the privilege of the front passenger seat".
A number of days later he tweeted: "There are opposing views of legacy events. I am proud of being part of the biggest escape in British penal history, in wake of the British systemic brutality of prisoners and deaths of 10 comrades on Hunger Strike."
Ms Long said a number of people made complaints to the Policing Board over the initial tweet and she had received three letters asking her to consider the removal of Mr Kelly from the board.
"The Policing Board carried out an unsuccessful attempt to secure an informal resolution of this matter, as the complainants were unwilling to pursue such a course of action. The board chair then passed the matter to me," she said.
"It is important to note that the test to be applied for whether there has been a breach of the code is considerably different in law to the test to be applied by me for removal of a member of the board from office, the latter being significantly higher: any decision by me would also be subject to review by the courts.
"Recognising the unusual requirement that one political representative should be asked to determine whether another political representative appointed by another political party should retain a board appointment, I sought advice from the departmental solicitor.
"Having considered that advice, it is clear that there are insufficient grounds even for holding an investigation into whether Mr Kelly should be removed from the Policing Board as the tweet, taken in the round with other statements of Mr Kelly, did not explicitly demonstrate a non-commitment to non-violence and exclusively peaceful and democratic means or otherwise suggest that there would be grounds to consider statutory removal."
Ms Long added: "I have already made it clear that I found the tweet offensive - but I am also clear that in discharge of my functions I must act in line with established legal standards.
"On that basis, I have accepted the legal advice provided and will not be taking further action."
DUP MLA Mervyn Storey and party colleague David Hilditch were among those who raised complaints in relation to Mr Kelly, and described the outcome as "deeply disappointing".
"The Justice Minister will need to explain to the people of Northern Ireland how she can decide on one hand that Gerry Kelly's tweet was offensive and thoroughly inappropriate yet tell the public there are insufficient grounds even to investigate whether he should be removed from the Policing Board," Mr Storey said.
Ulster Unionist MLA Mike Nesbitt and TUV leader Jim Allister both challenged Ms Long to publish the legal advice she received.
"Unless the Justice Minister is prepared to publish the legal advice she has received, she will be open to accusations of hiding behind it," Mr Nesbitt said.
Mr Allister added: "She should publish the advice. As the recipient, Naomi Long can wave privilege. Let the public see just why it is thought acceptable for a member of the Policing Board to joke about an event in which a prison officer was shot in the head and another died after suffering a heart attack during the breakout.
"This is yet another incident which will have many people asking fundamental questions about the nature of politics in Northern Ireland. Just why is it that Sinn Féin are untouchable?"
