Landowners of the White Island volcano have had the charges for safety failings leading up to the deadly 2019 eruption against them dismissed
The blast killed 22 people, including 14 Australians, and led to watchdog WorkSafe launching New Zealand's biggest workplace safety prosecution.
In total, 10 organisations and three individuals - Andrew, James and Peter Buttle - faced charges at Auckland's District Court.
On Tuesday, Judge Evangelos Thomas said a prosecution could not feasibly be brought against the Buttles as individuals.
Instead, their company Whakaari Management Limited (WML), will still face charges, along with other tourism operators.
"There is no evidence in this case of what happened behind the boardroom door at WML," Justice Thomas said.
"Without that evidence, I cannot assess what a reasonable director would have done had they been placed in that director's shoes."
The Buttles legally own Whakaari, the offshore volcano found 50km north of Whakatane, and earned around $NZ1 million ($A920,000) a year from tourism that took place on it, according to the prosecution.
"What happened was a shock to everybody," Peter Buttle told the court this week, according to The Guardian.
"I wish we knew and I wish we had the ability to have a bit of foresight, because what happened was a terrible disaster.
"We were very confident in the operators we have that they were extremely safety conscious."
Forty-seven people were on the island when it erupted in 2019, all as part of organised tours to the active volcano.
In June, tourism operator White Island Tours pleaded guilty to its charges.
All but one of the 22 killed were involved in one of its tours; 19 as customers from the Tauranga-docked cruise ship Ovation of the Seas, and two employees.
White Island Tours director Paul Quinn said the company "deeply regretted" its role in the tragedy.
The charges relate to safety measures in the lead-up to the eruption, and carry a maximum penalty of $NZ1.5million ($A1.4 million).
White Island Tours will be sentenced after the trial, which is expected to continue running for some weeks.
In 2022, Auckland-based scenic flight operator Inflite also pleaded guilty, ordered to pay $NZ267,500 ($A243,000) in fines and costs.
Two other government organisations, the National Emergency Management Agency, and research institute GNS Science, had charges dropped last year.
Meteorological agency GNS Science also pleaded guilty to one of its charges.