The 20-year-old singer reportedly made a comment to Orlando about his ex Miranda Kerr - who Biebs reportedly "went on a date" with while she was still with the Pirates Of The Caribbean actor.
After getting in each other's faces Orlando allegedly threw a punch in the direction of the former teeny bopper as onlookers cheered him on.
"They got in each other's faces and there were words," a source told the publication. "But they were separated by their entourages."
According to another source the altercation started when Justin attempted to shake the actor's hand.
"Justin was at one table, and Orlando was at another," the insider told Page Six. "But when Bieber and his party were later walking past Bloom's table, Orlando refused to shake Bieber's hand.
"Bieber said something rude to Orlando, like, 'She was good.'"
However, a pal of the singer's insisted he didn't make any rude comment and that "Justin didn't even know Orlando was there. But when they saw each other, it was Orlando who was just being an a-hole to Justin."
They were also adamant that Orlando didn't strike Justin. "There was no contact," the source said. "He missed. Then there was some 'tough-guy shoving,' and they were separated."
Miranda and Orlando announced their shock split in October 2013 after three years of marriage and said at the time that they had been separated for several months. Despite this, the split was said to be amicable and they would continue to be in each other's lives as parents to Flynn.
At the time Miranda told Harper's Bazaar Australia: "It's difficult for anyone to go through a separation, whether it's on a public scale or not.
"t was important for us long-term to preserve our friendship and the dynamic of being loving parents to Flynn so we dealt with everything openly and honestly.
"We respect each other and with respect comes understanding. When there's understanding, I guess everything is a little more harmonious."