CCTV has captured the moment a violent brawl erupted following a wedding reception in Sydney’s south-west.

Up to 40 people were involved in the fight which broke out just after 9pm outside the Emporium Function Centre on West Terrace in Bankstown, injuring two men.

“They were all dressed in suits, except two or three who were dressed casually,” witness Bilal Abdeen told 9NEWS.

“I started looking out the window when everything had finished. There were just a couple of people on the ground. Everyone else was screaming at each other.”

The bloodied scene of the brawl. (9NEWS)

The brawl broke out following a wedding reception in Bankstown. (9NEWS) (9NEWS)

9NEWS understands the violence erupted as a result of a lovers' tiff between another couple at the wedding.

The groom was reportedly so distressed by the incident that he collapsed several times during the night.

Mr Abdeen claimed he saw the men throwing punches, with one of them grabbing a metal pole to threaten another guest, as family and friends desperately tried to break up the brawl.

Two men were injured in the brawl. (9NEWS) (9NEWS)

A 19-year-old man suffered serious eye injuries and bruising to his face, head and body while a 28-year-old was left with a cut to the back of his head.

Police are yet to make any arrests but say that's likely to change over the coming days.