TORONTO - Lost: One gold chain witnesses at a downtown Toronto nightclub said belongs to pop star Justin Bieber.

Bieber was allegedly rushed by someone possibly an overeager fan on the dance floor at a downtown Toronto nightclub early Saturday around 3 a.m., when he left a designated VIP area.

Joallore Alon, 40, said he was at Uniun Nightclub on Adelaide St. W., near Portland St., when Bieber and his entourage showed up around 2 a.m.

From the back entrance, they came in and stayed for a bit, Alon said Saturday evening. He took off his shirt and had his sunglasses on and was hanging out in the VIP section behind the DJs stage. Apparently, he suddenly walks with his security into the dance section and thats when the alleged altercation happened.

Alon said he didnt see the ruckus itself, but saw Bieber leave through a back exit around 3 a.m., escorted by his security into a waiting SUV. The guards appeared to be looking for someone or something, such as a chain, he said.

Justin Bieber looked calm, he didnt look like he was agitated, Alon said. Someone was screaming, Wheres his chain? Grab his chain.

A dimly-lit photo taken at 2:29 a.m. Saturday showing a shirtless young man wearing a backwards baseball cap and his pants hanging low said to be Bieber is circulating on Twitter.

Another person inside the club at the time told the Sun it all happened very fast.

It appeared the guy grabbed the chain and ran off so quick nobody had a chance to do anything, he said.

And @TheDanLevy tweeted five minutes before that picture was taken, Has anyone seen Justin Biebers $40k gold chain? Someone just stole it off his neck in Toronto.

Calls to Biebers representatives at Universal were not returned and it was not clear if the chain was later found.

An insider who has been in clubs with the Baby singer before said his people would have torn the place apart looking for (the chain).

Pictures published by gossip website TMZ depict security staff pulling the man off Bieber and taking him to the ground. The gossip site said witnesses saw the 19-year-old Stratford native unleashing a fury of kicks during the melee.

A manager at Uniun who only identified himself as Graham, referred all media inquiries to Charles Khabouth at Ink Entertainment, a hospitality and entertainment company that maintains Toronto nightclubs, including the Guvernment and Koolhaus and This is London.

Attacked? Graham said skeptically, but would not confirm his nightclub was the venue where the exchange took place.

Multiple calls to Khabouth were not returned Saturday night.

Police were not called. A staff sergeant at 52 Division where the club is located said he had not heard anything about the incident.

Bieber famed for being photographed allegedly spitting on fans from a Toronto hotel balcony and peeing in a mop bucket while on his way out of a New York restaurant is no stranger to controversy, notorious for kicking paparazzi caught chasing him.

This wasnt the only nightclub Biebs hit Friday night. Around midnight, he arrived at Everleigh on King St. W., a manager at that club confirmed.

He just hung out, said the manager who didnt wish to be named. It was the first time Id seen him there.