Neo-Nazi leader filmed repeatedly punching security guard at Channel Nine building

The leader of an Australian neo-Nazi group has been filmed assaulting a Channel Nine security guard just hours before the network’s A Current Affair broadcast a segment about the organisation.

Thomas Sewell, one of the leaders of the neo-Nazi group National Socialist Network, was filmed assaulting the guard on Monday afternoon after he and another man came to the network’s offices in Melbourne before its tabloid current affairs program aired a segment about the group.

Footage of the assault, posted online and seen by Guardian Australia, shows the security guard ushering Sewell and the other man, who is holding a camera, out of the building.

The second man uses a racial slur against the security guard, who is black. He appears to put his hand over the camera. The video then shows Sewell strike the guard a number of times as the guard falls to the ground.

Victoria police confirmed officers had been called to an address at Docklands in Melbourne “following reports a man was assaulted”.

“It’s believed the victim was approached and assaulted by an unknown man at a Bourke Street business about 5pm,” a spokesperson for Victoria police said on Monday night.

“The offender, along with another man, both fled the scene and remain outstanding.

“The victim was transported to hospital with injuries. Police are investigating the incident and ask anyone who witnessed it to come forward.”

In a statement, a spokesman for Channel Nine said the company had handed CCTV footage of the incident to police and will cooperate with authorities in “seeking justice”.

“Thomas Sewell, who was featured in our A Current Affair report tonight on Neo Nazis, arrived at Nine Melbourne with a fellow member of his group late his afternoon,” the spokesman said.

“The pair demanded to see A Current Affair staff but were asked to leave. While they were being escorted from the building, a security guard was attacked and punched multiple times by Sewell.

“The pair then ran from the station. Victoria Police have been handed CCTV vision of the attack and the building’s security guard was taken to hospital by ambulance.

“Victoria Police will have Nine’s full cooperation in seeking justice. We are providing support to the security guard who was attacked. Nine is committed to providing a safe working environment.”

On Tuesday, the former Labor leader Bill Shorten was among those to condemn the assault. On Nine’s Today Show he called Sewell a “cowardly scumbag”.

“You know, our grandparent’s generation … would be shocked to realise we’re still arguing about Nazis,” he said.

Sewell is a self-avowed neo-Nazi who has long been linked to the far right in Australia.