An inquest into the Wieambilla shootings that claimed six lives including two police officers could be kept from examining "extremely sensitive" material.
Queensland State Coroner Terry Ryan held a second pre-inquest conference in Brisbane on Tuesday into the December 2022 killings.
Constables Matthew Arnold, 26, and Rachel McCrow, 29, were wounded then fatally shot at close range within 10 minutes of entering a rural Wieambilla property for a welfare check on a missing person.
The three suspects in the shooting, Gareth Daniel Train, 47, Nathaniel Charles Train, 46, and Stacey Jane Train, 45, also lit fires in an attempt to flush out a female officer who escaped being shot after taking cover.
The Trains' neighbour Alan Dare, 58, was shot dead when he attended the property to investigate the fire.
Members of the Train family and the families of the deceased officers watched the conference via videolink on Tuesday.
Barrister Ian Freckelton KC, appearing for the Queensland police commissioner, applied to have several items excluded from being considered by the coroner under a claim of public interest immunity.
The nature of that material cannot be published for legal reasons.
Dr Freckelton said there was a well-established precedent for certain material to be excluded from an inquest.
"The material is extremely sensitive ... the risk is that its public availability would erode the capacity of those protecting us to do their jobs and assist those who have malign intentions," Dr Freckelton said.
Barrister Patrick McCafferty KC, appearing for more than 30 police officers involved in the shooting, said he supported the material being kept from the public but it needed to be directly scrutinised by the inquest.
"We take issue with the attempt to conceal or keep secret from Your Honour (that material). It is deeply concerning to those I represent," Mr McCafferty said.
Queensland Police Union barrister Justin Greggery KC and a barrister for the Arnold and McCrow families also opposed the police commissioner's application, claiming it could affect the coroner's ability to address some of the issues and concerns at the inquest.
Counsel assisting Ruth O'Gorman KC said a compromise could be reached in which particular material was kept by the court and viewed only by legal practitioners or in hearings closed to the public.
Mr Ryan said he would respond to all applications for public interest immunity and non-publication orders by the end of the week.
The draft list of issues for the inquest has been expanded to consider what NSW authorities knew about the suspects before they opened fire on four police officers at Wieambilla.
The officers had attended the property to inquire about a missing person report concerning Nathaniel Train, in response to contact from NSW police.
The draft witness list now includes seven members of the NSW Police Force including the commissioner.
The inquest's draft schedule has the inquest's hearings starting on July 29 and running for at least four weeks.
