Cops are busy investigating that brawl at the South Pointe nightclub in Southhampton, N. Y., in which Justin Bieber and his crew engaged in a messy fight with a club attendee.

Not many details were clear previously, but now it's being reported that the police are looking into whether or not the Biebs ordered his security guards to beat up 22-year-old Wayne Rennalls over a waitress and a bow tie from H&M.

Police Sergeant Todd Spencer told Page Six, "That would be part of the investigation, whether Bieber directed [his bodyguards] or not."

A source who was at the club that night revealed further details, saying that the altercation "Was all over a little white H&M bow tie. One of the bottle girls liked it, so Wayne let her put it on. Justin was flashing all these girls with his flashlight. The girl with the bow tie went over to Justin and Wayne followed because he wanted his tie back. Then Bieber’s people got in his face."

Don't worry. He got his bow tie back, which is why everyone thought the nonsense was behind them.

"It escalated outside when we heard Bieber yelling and talking s---,” the paid informant continued. “He was screaming in Wayne’s direction, ‘Punk b----!’ Wayne thought somebody threw something at him. Wayne picked up a small rock and threw it back towards Justin."

"That’s when Wayne heard someone yell, ‘You done f---ed up now.’ Justin jumped out the sunroof of his car and slid down the car like he was in ‘Die Hard' ... He dropped his shirt and threw his hat and wanted to throw hands. His people surrounded Wayne, who was getting punched from all angles."

Added a friend of the victim, "When you have huge security guards backing you up, you get extra bold. This isn’t a macho thing. Justin was talking s--- from the safety of his car ... And then it was pandemonium.

Rennalls was hospitalized for complications from the fight, including a black eye, "busted lip" and a bruised rib cage. He filed assault charges the next day, but Bieber's reps are denying that he was involved. Because that's what they're paid to do.