A man, who didn't want to be named, was standing outside at his workplace when he saw the four steers making a run for it down the street.
He said they had escaped the nearby abattoir on Great South Rd then somehow managed to cross the busy, former state highway, before fleeing down Mt Richmond Dr into the domain this morning.
"We were just inside our fence line and they came bolting past us real quick, four in a row, one leading them and down the grass verge and around the corner, down to a no exit and bolted across the paddock into the domain."
Police were already at the abattoir so were pointed in the direction of where the cattle had fled.
The man said a chopper was then seen in the air above the domain before up to 20 shots were fired.
"They must have surrounded them all, from all sides, and there was about 20 gun shots and it's all quiet now ... the gun shots were pretty loud. I don't know if they were trying to round them up or scare them or what but presume they shot them."
"They must have crossed Great South Rd which is a pretty big road ... they were big steers that were obviously destined for the freezing works but got out somewhere."
A police spokesperson said officers were called to the area about 9.15am after reports four bulls had escaped from the abattoir.
"The bulls were on Great South Rd, Mt Wellington, impeding traffic and creating a safety risk for the public.
"The four bulls were being aggressive and, because of those safety risks, had to be put down by police officers at the scene."
Abattoir staff would now make arrangements to remove the cattle from the domain.
