Media organisations could be prevented from publishing video footage showing the circumstances of an Aboriginal Kempsey man's death in custody after NSW Corrective Services applied for the vision to be subject to a non-publication order.
David Dungay, 26, died in the prison hospital at Sydney's Long Bay jail in December 2015 after he was removed from his cell by a specialist riot response unit because he refused to stop eating biscuits.
Mr Dungay, who was being treated for mental health issues, became unresponsive and could not be revived after he was held in restraint positions by members of the Immediate Action Team on the afternoon of December 29 and injected with a sedative by a nurse.
A coronial inquest into Mr Dungay's death will be held in July.
At a preliminary hearing on Wednesday, the Coroner's Court heard the NSW Corrective Services Commissioner sought to have non-publication orders placed on two videos showing the circumstances of Mr Dungay's death, as well as several related documents, because they could reveal internal prison policies.
It was argued the videos - CCTV footage and handheld video footage that showed Mr Dungay being moved from one cell to another - could reveal the restraint holds prison staff used, the weapons they carried, locking mechanisms on the doors and the identities of corrective services staff, so parts would need to be blurred or blacked out.
The application was opposed by lawyers for Mr Dungay's family, who want the footage to be released in its entirety, and a lawyer from the ABC.
Counsel assisting the Coroner, Jason Downing, said the vision was "quite graphic" and part of it showed Mr Dungay being restrained, becoming unresponsive, and ultimately dying.
David Evenden, representing the Dungay family, said much of the material Corrective Services objected to in the footage was already available in the public domain and could be found with an internet search.
He questioned Terry Murrell, the general manager of statewide operations for NSW Corrections, who agreed under cross-examination that there was no attempt to conceal prison procedures from the inmates themselves.
But Mr Murrell said video footage, which could be watched repeatedly, would provide a chance to scrutinise the physical holds that had been used on Mr Dungay which could allow inmates to anticipate ways to evade such holds in the future.
"Our opposition to it is, if it's available on something like YouTube and can be played over and over again, then you can look at how you may avoid certain holds or how to maybe act in a certain way," Mr Murrell said.
Mr Evenden said Mr Dungay's death was "entirely avoidable" and the inquest should focus on the treatment he received for his "severe mental illness" while he was in the prison hospital, including why he was not transferred to the forensic hospital.
"Your honour, I raise this in open court, the family considers it a critical issue and something the inquest ought to look into," Mr Evenden said.
"What happened to Mr Dungay on that day could never have happened at the forensic hospital where there are no corrective services officers."
Deputy State Coroner Derek Lee said examining Mr Dungay's mental health treatment was "simply too remote for me to use my statutory power" and the inquest would instead look at a list of agreed issues.
The non-publication application will return to court on July 2.