WATCH: Neo-Nazi calls Black security guard a 'monkey' before viciously assaulting him

A white supremacist leader was caught on camera assaulting a Black security guard shortly after one of his associates referred to the guard as a "monkey."

Australia's The Age reports that Thomas Sewell, a leader of the far-right National Socialist Network, assaulted the security guard after the guard had forced him and his associate to vacate the Channel Nine building in Melbourne.

Sewell was at the building to protest against a news segment that was about to run on his organization, and at the start of the video Sewell complains that Channel 9 is trying to portray his organization -- which he openly admits "advocates for white people" -- as terrorists.

The security guard approaches Sewell and asks him and his associate, who is filming the encounter, to leave the building.

They do so reluctantly, and the guard follows them outside.

Shortly after exiting the building, the man filming Sewell says, "Dance, monkey!" to the security guard, who angrily tells him not to call him that.

The man with the camera then tells the guard not to touch him, although it's unclear from the video whether the guard is making physical contact with him.

Right after that, Sewell can be seen punching the guard in the face.

According to The Age, the guard was subsequently treated at a nearby hospital and then released. The publication also notes that Victoria Police possess footage of the attack on the guard and are investigating the assault.