He posted commentary following the verdict on Wednesday March 28th
Senator Aodhán Ó Ríordáin has apologised over a tweet he sent in relation to the Belfast rape trial verdict.
It comes after one of the defendants, Paddy Jackson, is set to take legal action against him.
Senator Ó Ríordáin posted commentary on his Twitter account following the verdict on Wednesday March 28th.
The tweet was subsequently deleted.
Paddy Jackson and the other three accused were acquitted of all charges against them.
Senator Ó Ríordáin has previously said: "The matter is now in the hands of my solicitors. I won't be making any further comment."
But in a tweet posted on Monday, he said: "My tweet of 28 March concerning the Belfast rape trial was not designed or intended to suggest that either Paddy Jackson or any of the other accused men were guilty or that the jury got it wrong.
"I apologise for any suggestion to the contrary.
"I accept that I was not privy to all the evidence put before the jury during the trial.
"I will not be making any further comment".
A statement from lawyers representing Mr Jackson on March 30th said they are to issue notice of intention to sue Senator Ó Ríordáin for "defamatory comments made by him in the immediate aftermath of the jury's verdict".
KRW Law said the legal action relates to a tweet sent to a number of other persons before it was eventually taken down.
It added that Mr Jackson "now finds himself resorting to the Civil Courts in order to seek protective action".
Senior associate of KRW Law solicitors, 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 related to a tweet sent to a number of others persons before it was eventually taken down."
She 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."