ACT Policing and Summernats organisers are investigating what appears to be a brawl involving patrons and security guards at the car festival.
Footage circulating on social media shows an altercation between attendees and security at Exhibition Park on Saturday, with several blows thrown.
It is unclear what provoked the outburst but one video shows a security guard wearing a pink hi-vis "crowd safety" vest approaching an attendee and appearing to punch him in the face.
At one point in the video, a security team member can be seen allegedly punching an attendee repeatedly as he stumbles back.
Security also appear to chase a man and kick him when he falls to the ground.
After police arrive on scene, one person could be heard saying "get the security guard".
In a statement to The Canberra Times, an ACT Policing spokesperson said they were aware of an incident that occurred on Saturday afternoon at Exhibition Park.
"Investigations into the incident are ongoing and no arrests have been made at this time," they said.
"No further comment will be made while investigations are ongoing."
Summernats co-owner Andy Lopez told The Canberra Times organisers would work with the relevant authorities to investigate.
Organisers and police were also required to shut down the cruise route at Exhibition Park for about 45 minutes on Saturday to clear people off the roadway.
Mr Lopez said that while the "boisterous" behaviour was "disappointing", the operations team and police worked together to get people off the track.
"We didn't want to see people jumping on the [roadway], getting on the cruise route and all that sort of thing," Mr Lopez said.
"But they did.
"It wasn't aggressive from the crowd or anything like that."
During last year's event, on a Saturday night, drunken patrons flooded over the concrete barriers and onto the cruise strip, turning it into a burnout pad and bullying security staff out.
Mr Lopez said the number of people who were evicted from this year's event hadn't been calculated yet but he expected it would be similar to past events.
"The number of evictions that we would have at Summernats, again, are never any different to what you would get at a footy match or a music festival," he said.
"[With] big crowds, there'll always be a couple of gooses who don't know how to behave and they're the ones that we have to deal with."
ACT Policing are also seeking witnesses after two people allegedly assaulted a security guard at a pub in Braddon on Sunday morning.
The four-day festival had attracted a record crowd of 130,000 people, as revheads flocked to enjoy burnouts, freestyle motocross, and a spectacular collection of cars.
By about 9am on Sunday, police had arrested two people relating to separate alleged incidents of anti-social behaviour at the event.
Three vehicles were seized for hooning in Braddon and officers also issued multiple defect notices.
Several streets in Braddon had been transformed into an outdoor modified street machine showroom as the festival expanded across the capital.
