A long-running legal battle around shark cage diving has taken another twist, after a court ruled the Department of Conservation does not have the power to grant authorisation to operators.
But the High Court judgment, released this month, did not address how the venture must be governed - or how public safety should be factored in.
Over the past decade, fledgling tourism ventures offering shark cage diving have emerged in the northeastern waters of Stewart Island, leading to a stand-off between operators and the paua industry.
In 2012, Maritime New Zealand hosted a multi-agency meeting of officials and groups interested in establishing commercial shark cage diving operations.
The following year, DoC released interim guidelines around potential risks to great white sharks from cage diving, at the same time acknowledging its "limited statutory authority to require permit applications for all commercial interactions with protected marine wildlife under the Wildlife Act 1953".
The guidelines were not intended to regulate shark cage diving, but to act as a guide for operators who, at that time, were not subject to authorisation under the act.
In 2014, then Conservation Minister Nick Smith announced that tourism businesses viewing great white sharks would need a permit as for whale, dolphin and seal watching - a solution seen as a tightening of rules and taking a firm approach to anybody who deliberately killed sharks.
The organisation representing the paua industry, PauaMAC5, backed permits, but argued permits should not be granted around Stewart Island.
PauaMAC5 argued that DoC should consider public safety when it issued permits under the Wildlife Act but DOC disagreed, asserting it was under no statutory obligation to consider public safety when making decisions under the act which, it said, was about the welfare of wildlife.
Evidence presented to the court addressed issues including the modification of shark behaviour, whether shark cage diving puts other water users at risk, and whether the shark cage diving operations could constitute an offence under the Wildlife Act.
But Justice Karen Clark said the key issue was whether the granted permits under the act were actually lawful.
Justice Clark ruled that the section of the act used by DoC did not give the department power to "authorise commercial shark cage diving operators, or any person, to attract sharks to a vessel, platform or cage for the purposes of viewing or filming the sharks".
But Justice Clark stopped short of ruling what law should now regulate shark cage diving - or determining that DOC must consider the safety of other water users.