Ultimate Fighting Championship star Conor McGregor is being investigated for alleged sexual assault by Irish police, The New York Times reports. McGregor has not been charged with a crime. The mixed martial arts fighter was arrested in January after a woman accused him of sexual assault, questioned by law enforcement authorities, and released pending further investigation, according to people familiar with the case. Irish media has reported on the case since last year, but did not name McGregor because of laws in Ireland that restrict media from identifying individuals charged with rape unless they are convicted. The controversial fighter announced his retirement from the sport on Tuesday. He was suspended from UFC for five months for sparking a brawl after losing a title fight in Las Vegas.

McGregor is one of the most successful MMA stars ever, but his career has been blighted by aggressive behavior outside the ring. In 2018, he was ordered to have anger-management training and perform five days of community service by a court after he had attacked a bus containing rival UFC fighters. In another incident this month, McGregor was arrested in Florida after smashing a fan’s phone.