Ulster and Ireland rugby player Paddy Jackson is to sue a Labour senator over an allegedly defamatory tweet he posted following Mr Jackson’s acquittal in the Belfast rape trial earlier this week.
In a statement issued by KRW Law, it said the legal action relates to a tweet sent by Aodhán Ó Riordáin to a number of other persons "before it was eventually taken down".
Senior Associate Marie Hans said: "I can confirm we have issued pre-action libel correspondence against a named Senator in the Republic of Ireland. The legal action relates to a tweet sent to a number of other persons before it was eventually taken down."
Ms Hans added: "We will not hesitate to repeat similar legal action against anyone, who deliberately or otherwise, sees fit to attack our client.
"We are examining carefully every item of social media commentary which seeks to challenge the integrity of the jury's full endorsement of our client's innocence. High Court proceedings will issue shortly in both Belfast and Dublin.''
Mr O Riordáin made no comment when contacted by RTÉ News.
Mr Jackson was acquitted of the rape and sexual assault of a woman at his home in Belfast in 2016.
His team-mate Stuart Olding was also acquitted of rape.
Blane McIlroy was found not guilty of exposure. Rory Harrison has been found not guilty of perverting the course of justice and not guilty withholding information.
The jury reached its unanimous verdicts on all counts after three hours and 40 minutes of deliberation.
Online comments over Belfast rape trial referred to AG
The office of the Northern Ireland Attorney General, John Larkin, has confirmed that comments made online by a juror in the Belfast rape trial have been referred to them.
The comments appeared several hours after the verdicts were delivered.
The juror made the remarks in the comments section of an article on Broadsheet.ie about the acquittals in the trial.
Speaking on RTÉ's Morning Ireland, Conor Gallagher of The Irish Times said the juror got involved in an online discussion about the trial.
He said the comments displayed an in-depth knowledge of the trial and indicated that the person was genuine.
He said the newspaper contacted the Public Prosecutions Office in Northern Ireland to query whether there was any issue or were the jurors allowed to comment freely and was told the matter was being referred to the Lord Chief Justice of Northern Ireland.
Mr Gallagher said the juror contacted The Irish Times last night to defend her comments, and said she had been contacted by the Lord Chief Justice’s office and advised to have the comments deleted, which she said she did.
He said the juror said her comments did not breach the trial judge's order not to discuss the jury's deliberations.
The PSNI said it is aware of "comments made on a social media platform".
It has also quizzed two people about alleged breaches of the complainant's right to anonymity.
"There is an ongoing police investigation and two people have been interviewed in relation to an offence under section five of the Sexual Offences Amendment Act 1992," said the PSNI spokesman.
"Two files have been forwarded to the Public Prosecution Service for consideration."
Under NI law, jurors are not permitted to disclose details of their deliberations in any trial.
Meanwhile, a number of media outlets are challenging reporting restrictions still placed on the case.
Restrictions preventing reporting on legal exchanges that take place in the absence of the jury usually fall away once the case is over, as the issue of prejudicing jurors is no longer relevant.
A number of outlets that covered the marathon trial are now seeking to get ongoing restrictions imposed by Judge Patricia Smyth lifted.
While the issue has been listed for a mention hearing before the judge on 25 April, lawyers for press and broadcasters are endeavouring to have the matter dealt with next week.
Separately, two people have been questioned by police in relation to naming the complainant in the case online.