Conor McGregor was captured on video apparently sucker-punching an older man inside a bar in Dublin earlier this year. The attack happened as the retired MMA fighter was enjoying shots of whiskey with other patrons.
A spokesperson for An Garda Síochána, Ireland's police service, told CBS News that they would not comment on McGregor specifically, but they're investigating an assault at the bar that happened around the time matching TMZ's video.
"Investigations ongoing in relation to this incident and no arrests have been made to date," the spokesperson said.
The controversial fighter announced in March that he is retiring from mixed martial arts. Earlier that month, he was arrested for allegedly smashing a fan's phone in Miami Beach.
McGregor returned to UFC last fall after a hiatus during which he made his boxing debut, a loss to Floyd Mayweather in the richest fight in boxing history.
He was suspended from UFC for six months and fined $50,000 for a brawl after his loss to Khabib Nurmagomedov in October. McGregor said he regretted getting into the backstage melee.