Boomerang used in UFC Sydney street brawl

A Brazilian heavyweight UFC fighter has been charged for allegedly using a boomerang to attack a fellow fighter in a daylight street brawl outside a luxury hotel in Sydney's CBD .

Fabricio Werdum, 40, allegedly threw the boomerang, still in its plastic shopping bag, at American welterweight UFC fighter Colby Covington during the fight on George Street at about 1.30pm on Thursday.

Another UFC fighter, New Zealander Dan Hooker, filmed the altercation which shows Werdum hurling the boomerang, which flew out of the bag as it slammed into Covington's neck.

The UFC says a full investigation into the street fight will be carried out.

"UFC was made aware of the altercation between Fabricio Werdum and Colby Covington at the organisation's host hotel in Sydney, Australia," the statement said.

"The organisation will conduct a full investigation to determine if the Athlete Conduct Policy was violated before taking any further action on this matter."

Following the assault Covington filmed himself yelling abuse including racial slurs at Werdum.

"F*** Brazil "f*** Fabricio Werdum, little b******. F*** Brazil," Covington says to his Instagram live video.

"A bunch of filthy animals. And they wonder why they get talked to like that, because they're a bunch of animals."

Werdum was charged with common assault and is due to face Sydney's Downing Centre Local Court on December 13.

He is in Sydney for a UFC fight on Sunday where he is scheduled to take on Poland's Marcin Tybura at Qudos Bank Arena.