Police in New York have launched an investigation into reports members of Justin Bieber's entourage were involved in a bloody bar brawl on Saturday night (03Aug13). The pop superstar visited the South Pointe nightclub in Southampton in the early hours of morning with a group of friends and a number of bodyguards, but it descended into chaos after the singer allegedly became involved in a vicious verbal spat with another clubber. Bieber's bodyguards ushered him out of the building before a brawl broke out in the club, allegedly involving members of the teenager's entourage, and the fight then reportedly spilled out into the parking lot. Local police have now launched an official investigation after a male partygoer filed a report alleging he was knocked out on the concrete outside the club and subsequently hospitalised, according to TMZ.com. Editors of the website report Bieber, 19, remained in a parked SUV during the trouble, but jumped out of the sunroof and stood on the hood of the vehicle as the fight flared up. The singer is not believed to be a target of the investigation.