A jury has been sworn at the High Court to hear a civil action for damages against Irish mixed martial arts fighter Conor McGregor and another man for the alleged sexual assault of a woman.

Justice Alexander Owens told the jury that the allegation is that, Nikita Ni Laimhin, a hair colourist, was sexually assaulted by Mr McGregor and another man on December 9 2018.

The judge said that it is alleged that the pair had “in effect raped her” on that date.

He told the jury that it is not a criminal case, but a civil action for assault.

The court heard that if it is proved, then it is a civil wrong and the plaintiff is entitled to compensation of damages.

The jury was told that they are judges of fact as to what happened and will have to draw a conclusion and it will be based on their decision.

Mr McGregor, wearing a white shirt and a blue suit, is attending the High Court in Dublin.

The action is expected to last around two weeks.

Justice Owens warned the jury not to become their own “private detective” and carry out their own independent research into the case.

“You make your decision and listen to the evidence and make your decision based on the evidence,” Justice Owens said.

“Anything that you hear or see about this trial, or anything about the circumstances of the trial that is not received in court, cannot be considered by you.”

He warned the jurors not to get into discussions with family members about the case when they return home in the evenings, and not to ascertain their opinions on evidence.