An indigenous teenager who had his legs kicked out from underneath him while he was arrested was 'distraught' following the ordeal.
Ali Mongta-Finn, the 17-year-old's sister, told Triple J Hack her brother shouldn't have been mistreated for being 'lippy'.
The teenager told an officer he would 'crack you in the f**king jaw, bro', following a verbal altercation at Eddie Ward Park in Surry Hills about 5pm on Monday.
In response, the officer handcuffed him and kicked his legs from underneath him at the same time, sending the boy tumbling face first into the footpath below.
A 16-year-old boy suffered a chipped tooth and bruising all over his body after he was thrown to the ground by a police officer
Police are conducting an internal investigation into the officer's approach to the arrest, and placed him on restricted duties for the duration of the investigation.
Ms Mongta-Finn said her brother was distraught and his teeth were chipped during the ordeal.
'When he came back home later that night, he was shaken up,' she said.
'He was very sore this morning and he was distraught.
'Teenagers, they're lippy, but you don't just abuse children because they're lippy.'
NSW Police Commissioner Mick Fuller on Wednesday admitted there were 'other ways' the officer could have dealt with the matter, other than the leg sweep.
A police officer was filmed throwing a young indigenous man to the ground after he was threatened
Following his arrest, the family claim he was taken to holding cells before being transferred to St Vincent's Hospital via ambulance, where he spent the night waiting for results from x-rays to his shoulder, knee and elbow.
NSW Police Commissioner Mick Fuller (pictured) on Wednesday admitted there were 'other ways' the officer could have dealt with the matter, other than the leg sweep
He said the officer in question had worked in the force for three-and-a-half years and had no record of complaints, and likely regretted the way he arrested the teen.
The teen was released without charge and taken to St Vincent's Hospital for treatment.
His family claim he suffered cracked teeth and bruising across his entire body.
'He has a bruised shoulder, cuts and grazing to his knee, face and elbow, and chipped teeth,' a relative said.
'This is a case of two things - is it reasonable for someone to swear and threaten a police officer? And then, is the force the officer used reasonable?' Mr Fuller told 2GB Radio.
'I don't know what happened before in terms of the lead-up but there was probably other ways the officer could have dealt with that matter, no doubt.
Footage shows the officer, who was patrolling in Surry Hills in Sydney at the time, swipe the feet from underneath the man during the arrest (left). While on the floor, the young man appeared to struggle to manoeuvre his arms behind his back and was wailing (right)
The vision divided readers - some of whom said he should have been detained following the threats while others said the police officer was too harsh
'I totally accept that officers need to show restraint.'
Footage of the arrest was captured on a mobile phone and posted on social media.
A bystander can be heard yelling: 'You just slammed him on his face. He's in pain.'
The teenager's parents and other relatives will speak about the incident at a press conference at New South Wales parliament on Wednesday alongside Greens MP David Shoebridge.
NSW Police on Tuesday said the professional standards command was investigating and the constable involved had been placed on restricted duties.
'He has a bruised shoulder, cuts and grazing to his knee, face and elbow and chipped teeth,' a relative said
'We're all aware of incidents that have taken place in the United States over the past week and we're aware of the sensitivities around what's occurring overseas,' Assistant Commissioner Mick Willing told reporters on Tuesday.
'Am I concerned about what I'm seeing in the footage? Absolutely. But I'm equally concerned about others who may use the footage to inflame it and turn it into something it's not.'
Redfern Legal Centre has also referred the matter to the independent police watchdog.
The footage emerged on the eve of a scheduled Black Lives Matter protest in Hyde Park, similar to the protests occurring in America following the death of George Floyd last week.
Officer Derek Chauvin (pictured) was identified as the officer pinning down George Floyd in video footage that was widely shared last week