Krista Kach, 47, died following a 10-hour stand-off with police in Newcastle in September and it was later revealed a bean-bag round had punctured her body and impacted her heart.
The Law Enforcement Conduct Commission (LECC), which monitors all NSW Police investigations into so-called critical incidents, requested to view the force's manual guiding the use of "less-lethal" measures.
But NSW Police launched an appeal in the Supreme Court to stop it being compelled to produce the document in its entirety, arguing it contained sensitive information that was not relevant to the watchdog's monitoring.
The manual manual addresses more than the use of the bean-bag rounds and deals with police tactics and methodologies more generally, including those used by law-enforcement agencies overseas, the court was told on Thursday.
NSW Police lawyer David Hume said the force respected the public-interest need for transparency, however there were legitimate concerns about the information being disclosed beyond the commission.
Police are also resisting an order to disclose personnel logs, which Mr Hume argued contained the names of operatives and could "lead to reprisals".
The commission argued those grounds were not legitimate objections to handing over the material, the court was told.
Mr Hume said one of the concerns held by police was that it could pass on the information to state parliament and it could then make its way into a parliamentary report.
"We did invite LECC to undertake not to on-disclose the information to parliament and that was refused," he said.
The three justices hearing the appeal questioned why the parties had been unable to reach an agreement to disclose only those parts of the document that relate to the use of bean-bag rounds.
Lawyers for the commission are expected to argue part of the agency's role is satisfying itself no elements had been overlooked, including material that might have been deemed irrelevant by police.
The commission was legally entitled to obtain documents in full that it deemed relevant to its role of monitoring police investigations into critical incidents, the court heard.
Mr Hume said the issue being considered at the hearing was not only key for the existing case, but was also an "important and recurring issue" when it came to dealing with the relevant laws.
Police were initially seeking to have non-publication orders placed on the court proceedings, but they withdrew the application prior to the hearing starting.
The case continues.
