An officer then removed the man from the station, saying he believed the man was going to assault him or one of his colleagues.
The man alleged that the officer choked him, which the officer denies.
The man said he feared for his life and "kept going in and out and starting to blackout".
The choking allegation was not substantiated.
But the IPCA said in a report released on Wednesday that CCTV footage shows that the officer initiated a physical confrontation.
"When the force was used, the man was walking away from the officer and moving towards the exit door with his hands by his side holding his property.
"The authority does not accept that the officer used force for the purpose of defending himself or his colleagues."
The authority said the officer used pre-emptive force as opposed to a response to an immediate threat of harm.
"As such the use of force was excessive and not justified," it said.
"He was not acting in self-defense, and his use of force was excessive and not justified," he said.
After the 30-second physical altercation, the officer moved the man through a doorway. There is no footage of their interaction in the corridor as there is no camera.
Outside the station, officers in a passing police car saw the man kick a temporary fence and he was arrested again.
Eastern District Commander Superintendent Jeanette Park said police accepted the use of force against the man was unjustified.
Restraining an offender with an arm around his neck is "no longer an approved tactical option", she said.
Police would identify any lessons to be learned, and whether there are any training opportunities for staff involved.
