An arrest, during which a man was seriously injured outside the Iranian embassy in Canberra, has been referred to the Australian Federal Police's internal integrity unit.
Hamid Sotounzadeh was arrested on Thursday morning for failing to comply with a lawful direction during a protest outside the embassy, where he has frequently protested over the past four months.
Video from the incident shows an officer repeatedly pushing Mr Sotounzadeh and telling him to "get back".
Mr Sotounzadeh then suffered serious injuries, including three rib fractures – though the exact manner in which he was injured is unable to be verified.
Subsequent videos shows him lying on the ground, seemingly unresponsive, and being cared for by friends and officers.
Mr Sotounzadeh is currently being treated in Canberra Hospital, and said he is awaiting further testing to confirm other potential fractures in his neck and lower back.
In a statement, an AFP spokesperson confirmed Mr Sotounzadeh had complained of back pain after he was handcuffed.
"Those handcuffs were removed and an ambulance was called," the spokesperson said.
Mr Sotounzadeh was released from police custody before paramedics took him to hospital.
He has not been charged over the incident.
The AFP spokesperson said Mr Sotounzadeh had behaved aggressively towards officers prior to his arrest.
They said the AFP was aware of Mr Sotounzadeh's claims that he was injured during the arrest.
"The AFP is seeking to ascertain the veracity of those claims and has referred the incident to the AFP's internal integrity unit, Professional Standards, for investigation," the spokesperson said.
