The landowners of a New Zealand volcano that fatally erupted in 2019 have rejected arguments from the country’s workplace safety regulator that they ultimately managed and controlled activities on the island and bore legal responsibility for whether visitors to it were safe. When White Island/Whakaari exploded on 9 December 2019, 22 people were killed – 17 of them Australians – with 25 others injured. It prompted renewed debate about controls for natural hazard tourism in New Zealand. A lengthy trial for Whakaari Management Limited (WML), a firm co-directed by the three brothers who own the active volcano off the east coast of the North Island, concluded in the Auckland district court on Thursday. It had begun with emotional and graphic accounts from the eruption’s survivors – many of whom were cruise ship passengers – who said they did not know the dangers they faced when they walked to the crater of Whakaari. Investigators from the government agency WorkSafe charged a dozen parties with health and safety law breaches after the disaster, including tourism firms, science agencies and the island’s owners. Six organisations admitted to the counts against them before the case came to trial. But despite the investigation being billed as the most complex of its kind in New Zealand’s history, the case against the remaining parties started to crumble after the trial began in July: five firms or people, who had pleaded not guilty, had the charges against them dismissed after prosecution evidence concluded last month. With only one defendant remaining, closing arguments this week contested whether WML – a company set up to grant licences to tourism operators on the island – was an active manager with legal responsibility for how safely those businesses operated on their land, and whether actions they took discharged any obligations they had. For the prosecutor Kristy McDonald, the case turned on money; Andrew, James and Peter Buttle earned NZ$1m (£500,000) in fees and commissions from the licences their company granted to tour operators, she told the court. The profits were “not reinvested into managing and understanding the risks” of tourism on an active volcano, McDonald said. The firm had obligations under the law “to the tourists whose fees funded its business” because they were engaged and active managers who had the discretion to stop operators using their land. But James Cairney, the lawyer for WML, said the volcano’s owners had set up the firm solely to manage the financial side of granting licences, and the existence of a commercial interest was not anything to be ashamed of. “The attacks on the financial aspects in this case really don’t assist any of the key issues for your honour’s determination,” said Cairney, referring to prosecution remarks throughout the trial that the owners had put profits before safety. The company had no active control of day to day activities on the island, no presence on Whakaari or in the region, and was set up solely to licence access to other firms, he added. Cairney said: “Whakaari is not a business, it’s an island. “Was it hazardous? Yes. WML doesn’t shy away from that. Granting rights of access to an active volcano is really just … the landowner granting rights of access to hazardous natural land, which occurs all over New Zealand all the time.” Nothing in the licences granted to the tourism operators promised an ongoing role for WML in operations on the island, said Cairney. He added that in any case, the firm had done everything the law required of landowners. The trial has been the biggest test yet of New Zealand’s sweeping 2015 reforms to its workplace health and safety laws – the most significant in two decades – which shifted responsibility for workplace hazards to those “conducting a businesses or undertaking”, who must be proactive on matters of risk rather than relying upon regulators. The changes, which brought New Zealand law into line with those in Britain and Australia, were prompted by the death of 29 workers in the 2010 Pike River mine explosion. Whether WML should reasonably be considered a responsible party – and if so, whether it failed in its duties – was at the centre of the Whakaari trial. The firm and its directors, who had individual charges against them dismissed last month, appeared to believe that they “did not owe any duties under the law”, McDonald said. “WML effectively points the finger at everyone else,” she added. A science agency and local emergency managers came under scrutiny during the case over their readiness for such a disaster. It was “dangerous” to suggest “a single, private company” had a responsibility to determine “societal risk” of an activity, said Cairney. After nearly two months of evidence from the prosecution, Thursday’s remarks from Cairney were the first time the island’s owners have advanced a defence against the charges. The number of deaths and the traumatic nature of the disaster – which made global headlines – had created a risk of “hindsight bias” in a “desire to hold someone accountable”, Cairney said, in an “orthodox” case of landowners providing access to land for adventure activities. Judge Evangelos Thomas, who is deciding the case, said he would give a verdict on 31 October. The six parties that pleaded guilty to charges against them will be sentenced in Whakatāne, in Bay of Plenty where Whakaari is located, on 19 October. They include the tourism firm that brought visitors to the island by boat; the eruption killed two of the company’s guides. The companies face maximum fines of NZ$1.5m if found guilty.