Queensland police are reviewing footage of an arrest in Brisbane's Fortitude Valley from the weekend, which appears to show an officer punching and kneeing a man.
The video shows several officers arresting a man on Saturday night, reportedly after he had been ejected from a nearby club.
Jacob Grady, who filmed the arrest, said the man was "getting pulverised".
"At the start I was worried about the police officers but by the end I was worried about the guy and about how badly hurt he would get," Mr Grady told the Seven Network.
"In the end his face was on the ground and there was so much blood on his face."
The Queensland Police Service said in a statement on Wednesday it would "examine the video and all circumstances leading up to the incident".
Police Minister Bill Byrne, confirming he had seen the footage, defended police training and said officers knew the "limits of their powers and application of force".
"If there is a case to answer for an officer, I can assure you that will be dealt with," he said.
Police union president Ian Leavers stood by the officers, claiming the man had king-hit one.
"Police were viciously attacked, through simply doing nothing more than their job," he said.
"If you're going to viciously attack police, you can expect that you will be restrained and that whatever force will be used will be required, that's the way it is".
