Hannah Thomas was punched in the face by a police officer, her lawyers claim | Australian police and policing

Body-worn camera footage shows a police officer punched the former Greens candidate Hannah Thomas in the face during a pro-Palestine protest, her lawyers have claimed, resulting in “extensive and serious injury to her eye”.

Thomas’s lawyers at O’Brien Criminal and Civil Solicitors have said the 35-year-old will sue the state of New South Wales and called for police to withdraw the two criminal charges against her.

Thomas was arrested at a protest in Sydney on 27 June that was attended by about 60 people. She was taken to hospital and last week underwent a second round of surgery amid fears she could lose sight in her right eye.

As a Greens candidate, Thomas ran against Anthony Albanese in the seat of Grayndler at the federal election.

Her lawyers said they had taken the unusual step of commenting on the case while criminal proceedings against their client were under way after viewing the footage. Thomas has been charged with resisting police and refusing or failing to comply with a direction.

“My office has now viewed all available footage of the incident giving rise to the moments leading to the injury to Ms Thomas’ eye on the 27th of June, and I am satisfied that Ms Thomas was punched in the face by a male police officer, causing extensive and serious injury to her eye,” Peter O’Brien alleged.

He claimed Thomas was “an innocent victim of gratuitous police brutality and excessive use of force”.

Days after her arrest, the NSW assistant police commissioner Brett McFadden told ABC radio that he had viewed the body-worn video and there was “no information at this stage that’s before me that indicates any misconduct on behalf of my officers”.

“She was given a move-on direction,” he said then. “She [allegedly] failed to comply with that. Attempts were made to arrest her. She resisted and other people became involved. A scuffle ensued and she sustained the injury we believe during the course of that arrest.”

O’Brien said he had written to NSW police and the office of the director of public prosecutions, submitting that the charges against Thomas should be withdrawn and dismissed.

“Our firm is now furnished with instructions to proceed with a civil claim for compensation against the State of NSW for the actions of the NSW police officers connected to her apprehension, injury, detention, and prosecution,” he said.

“Torts likely to be pursued against the State include assault and battery, false imprisonment, malicious prosecution, misfeasance in public office, and collateral abuse of process.

“It is noteworthy that this occurred against the backdrop of the State government’s attempt to broaden police powers in relation to public assemblies such that they are arguably contrary to constitutional principles.”

Last week police dropped a charge against Thomas that relied on a rarely used emergency power introduced after the 2005 Cronulla riots that gives police powers to quell “large-scale public disorders”. Police replaced the charge with refusing or failing to comply with a direction.

The 27 June protest was outside SEC Plating, which protesters claimed was manufacturing parts used in the F-35 jet program. SEC Plating has denied this.

The NSW Greens spokesperson for justice, Sue Higginson, called for charges to be dropped against Thomas and four other protesters, for McFadden to stand down and for an investigation into his conduct be launched. She also called for the officers at the protest to be charged.

Higginson accused McFadden of misleading the public, laying incorrect charges and making inconsistent statements.

On Friday Thomas told Guardian Australia it could be months before she knows how much sight she will recover in her right eye. She said she had undergone a second surgery on Thursday and was recovering well: “It’s a long road ahead.”

NSW police said they could not provide a response to the Guardian Australia’s questions about the lawyer’s claims “due to the ongoing critical incident investigation, which is being reviewed by the Professional Standard Command and oversighted by LECC [the Law Enforcement Conduct Commission”.

“As for any critical incident investigation, the circumstances of any serious injury and the conduct of police, is incorporated into that investigation, and that investigation is ongoing.”