The apology came hours after Ulster Rugby and the Irish Rugby Football Union (IRFU) announced that Gilroy would be subject to an internal review into the fallout of the rape trial and, as a consequence, would not be available for selection for Ulster's next match.

Ulster and Ireland teammates Paddy Jackson, 26, and Stuart Olding, 25, were unanimously acquitted last week of raping the same woman at a house party at Jackson's home in June 2016.

Part of the subsequent review being carried out by Ulster Rugby and the IRFU focuses on a series of messages sent by the players in the wake of the incident.

Gilroy, who was not involved in the incident, sent one of the sexually explicit messages that featured in conversations outlined to the jury during the nine-week trial at Belfast Crown Court.

The Whatsapp sent to Olding asked "Any sluts get f*****?", to which Olding replied "Precious secrets."

The sender of the message was referred to only as "CG" during court proceedings.

Gilroy posted the apology on his Twitter account on Tuesday night:

I would like to apologise unreservedly for any offence cause by the Whatsapp message I sent in June 2016.

"I would just like to clarify it was sent privately, not part of any group chat.

"Regardless, my comment was totally inappropriate and is not an accurate reflection of my beliefs nor Ulster Rugby's values.

"I take full responsibly for my actions and in future will ensure that language I use in private or public better reflects who I am and what I stand for. I am deeply sorry for the hurt my comment has caused. Craig."

Gilroy will not play in Saturday's PRO14 game against Edinburgh.

A statement by Ulster Rugby and the IRFU said:

Ulster Rugby and the IRFU confirm that as Craig Gilroy is subject to an internal review, he will not be available for selection this weekend.

Thousands of people have attended rallies across Ireland to express support for the woman at the centre of the case following the outcome of the trial.

Jackson and Olding have expressed a desire to return to playing action. But they remain relieved of their duties pending the outcome of the sporting review.

Jackson was also found not guilty of sexual assault.

Two other men were unanimously acquitted of lesser charges related to the same incident in June 2016.

Blane McIlroy, 26, was acquitted of exposure while Rory Harrison, 25, was found not guilty of perverting the course of justice and withholding information.

The high-profile trial, which ran for 42 days, generated an unprecedented level of public attention and prompted calls from Jackson's defence solicitor for a crackdown on social media comment during criminal proceedings.

It has also renewed the debate on whether defendants in rape trials should also be entitled to anonymity, with their names only being revealed if they are convicted.

- PA