Police were called to a Meriton building site on Sexton Avenue in Castle Hill about 7am, after reports that up to 50 people had become involved in the brawl.
It is alleged that the brawl on Tuesday was the second fight involving the father and son, who police said were fired from the site last Friday.
After being let go last Friday, the duo returned to the Castle Hill site on Monday morning, allegedly armed with hammers, according to Hills Police Area Commander Detective Superintendent Naomi Moore.
“Two contractors had been allegedly assaulted by subcontractors, who I believe had been terminated from the site last Friday,” Moore said.
She said they were initially armed with hammers, but they put them down and “engaged in a fist fight with two of the contractors” on Monday.
They left before the police arrived, before allegedly returning yesterday with backup.
“On Tuesday, the same two male offenders returned to the site, this time with some other people who were not known to work at that site previously,” Moore alleged.
Video of the struggle showed dozens of people trading blows, with one man appearing to be kicked in the head with a steel-cap boot, and another beaten on the head with a hard hat.
By the time police arrived, the fight had broken up.
Paramedics took a 43-year-old and a 55-year-old man to hospital with minor injuries, and they have both since been released.
Moore said there had been a significant investigation, with the help of the companies, to identify the men involved.
“The two main offenders, who I will allege are probably the ringleaders in this, have presented themselves to the police station,” Moore said.
“On the Monday, there was some frustration and anger from their termination on the Friday, and whether they’ve gone there to resolve it, one would argue they haven’t as they’ve attended with hammers.”
They were arrested at Castle Hill Police Station at about 11am.
They are expected to be hit with charges of affray, assault, and intimidation over the two alleged incidents.
Police are still looking for up to 11 other people over the incident.
Moore said officers have footage, including CCTV from nearby premises, that will help to identify them.
“It blew my mind if I’m honest, I’ve not seen anything like that before.”
She urged those people to come to police, “before we come and knock on their door”.
“The behaviour is absolutely appalling, and we won’t stop until they are in custody,” Moore said.
In a statement yesterday, Meriton said the contractors involved in the fight had been fired.
“Meriton promotes safety and does not condone any violent or threatening behaviour on its job sites, whether employees, subcontractors or visitors,” it said in a statement.
“No direct Meriton employees were involved in the incident that took place today on the street, outside of its Castle Hill construction site.
“Appropriately, the local police were called who have since intervened and we have ascertained that there were no serious injuries.
“The contractors involved in the fight have been immediately terminated.”
