Brazilian UFC fighter Fabricio Werdum​ has been charged by police after allegedly assaulting rival fighter Colby Covington with a boomerang outside a Sydney hotel on Thursday afternoon.

According to police, two men got into an altercation about 1.30pm outside the hotel on George Street.

In a video posted online by New Zealand UFC fighter Dan Hooker, a man who appears to be Werdum, 40, can be seen gesticulating and pointing at Covington, 29, before launching a boomerang at him from close range.

The boomerang strikes Covington in the neck, but it does not return to the thrower.