New Zealand volcano investigation could take a year, says Ardern

An investigation into whether anyone was at fault for the deaths of at least 16 people in a volcanic eruption in New Zealand last week could take as long as a year, the county’s prime minister Jacinda Ardern said on Monday.

A week after the eruption of Whakaari, also known as White Island, 14 people remain in burns units around New Zealand, 10 of them in critical condition, 13 more were airlifted to hospitals in Australia where one person has since died. The bodies of two people are still missing.

New Zealanders observed a minute’s silence on Monday afternoon to commemorate the disaster. Ardern was in a cabinet meeting, where ministers observed the event, and Judy Turner, the mayor of Whakatane – the town closest to the island – led a moment of remembrance there for hundreds of mourners, according to Radio New Zealand.

Related: White Island volcano: what we know about the victims

Specialists from New Zealand’s military hoped to return to Whakaari on Monday to search the nearby waters for two bodies that they could not find during a perilous recovery mission to the island on Friday. During that trip – a gruelling and physically demanding operation – the bodies of six of the eight people unaccounted for were found.

Divers returned to the island on Sunday to look for the remaining two, who were believed to be in the ocean off the island, and returned empty-handed; weather conditions at sea prevented a recovery mission on Monday.

“Police with the navy will continue their recovery operation for the two remaining victims,” Ardern said onMonday, adding that searchers would reassess the risk “each day.”

White Island’s volcanic alert status is currently rated at two out of five, the same level of risk as the day it erupted.

Related: The unanswered questions behind New Zealand’s volcano tragedy

Whether tourists should have been on New Zealand’s most active volcano last Monday, and whether anyone failed to do anything that could have kept them safe, will be a question for the government agency WorkSafe, in an investigation that is likely to take a year, Ardern said.

The inquiry will decide whether charges should be brought against any named individuals who are found to have violated New Zealand’s workplace health and safety laws. Ardern told reporters at parliament in the capital, Wellington, on Monday that as well as the tour operators who took the visitors to the active volcano when it erupted, cruise ship companies and landowners could also come under scrutiny.

Many of the tourists who were visiting White Island when it erupted were passengers on the cruise ship Ovation of the Seas, which was docked in the nearby Port of Tauranga. The island is owned privately by a family from Auckland, who sold leases to four tourism operators.

A second investigation by New Zealand’s chief coroner is also under way.

Neither inquiry will examine the actions of emergency services in the immediate aftermath of the eruption. The authorities were criticised by some of the grieving families for their decision not to allow first responders to return to the island after an initial trip to rescue survivors due to safety risks.

Tourism and legal analysts told the Guardian last week that New Zealand’s “no fault” accident compensation system had given rise to more risk-taking in the adventure tourism sector than was considered acceptable in other countries.

The scheme, known as ACC, covers the treatment costs for all accidental injuries in New Zealand but bars the injured from bringing lawsuits for negligence.

“I simply do not agree that ACC in any way has led to there being less focus on health and safety issues,” Ardern said, adding there were “regulatory regimes” that managed risks to tourists.

Ardern said on Monday that $5million NZD had been set aside to help support small businesses in the area, as well as those on the West Coast of the South Island who were cut off by flooding last week.

The small, tourist town of Whakatane, in the economically-deprived region of Bay of Plenty has long been reliant on the tourist draw of White Island as an anchor for its economic survival.

A panel of government ministers and public officials would decide on the criteria for distributing the funds, Ardern said.

The prime minister said it was also not for her to say whether White Island would be reopened for tour groups in the year that the inquiry would take to complete.