Billy Slater not yet off hook for punch as NRL Integrity Unit steps up investigation CCTV footage of Billy Slater in front of the Mojo nightclub. INVESTIGATORS from the NRL Integrity Unit have interviewed an English couple claiming to be at the centre of Billy Slater's infamous Manchester nightclub punch. As revealed in The Sunday Telegraph, the Integrity Unit is looking into allegations that, moments before Slater struck a man outside The Mojo nightclub, a 35-year-old woman was knocked to the ground by another Australian player. A group of Kangaroos, which include the Test fullback, have been linked to the alleged altercation which was brought to the attention of Integrity Unit boss Jim Doyle over the weekend. Billy Slater scores in the World Cup final. In his lengthy email, a copy of which has been obtained by The Daily Telegraph, the Englishman says the now infamous confrontation occurred only after his girlfriend, "Natalie," was knocked over by an Australian player as they tried to hail a cab. As part of the fresh investigation, Integrity Unit member Alby Taylor, a former police superintendent, interviewed the UK couple on Monday. Doyle was unavailable for comment yesterday however an NRL spokesman confirmed the investigation was "ongoing." Speaking with The Daily Telegraph last night, the UK couple - who have asked to remain anonymous until the investigation is complete - confirmed they had spoken with an NRL official. "We just answered all his (Taylor's) questions about the night in question," the Manchester businessman said. Australian team management have previously insisted Slater was simply returning to Mojos for a jacket when "king hit" by a local who mistook him for a queue jumper. CCTV footage showed the man pushed Slater with an open hand. Both the couple and a third female eyewitness strenuously deny suggestions their complaint is payback for Slater's heavy-handed response to being assaulted. The trio have also provided log numbers for two calls made to Manchester police at 2.41am and 2.44am - claiming both were made during the initial incident. Billy Slater (bottom) is "cuffed" outside the bar. Both women also made official complaints to police but later withdrew them. The Slater incident first made headlines in November when, having returned to Manchester after thrashing Ireland 50-0 in Limerick, the Melbourne fullback was detained by British police following a night out but was later released without charge. Mojo nightclub in Manchester.