Volatile White Island is at risk of erupting again, leading rescuers to contemplate a possible high-speed, in-and-out mission to recover victims' bodies.
However, the plan might need the consent of victims' families, police Deputy Commissioner Mike Clement said.
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This was because quick-moving recovery teams ran the risk of missing or leaving behind vital evidence, which in turn could prevent some victims' bodies from being accurately identified.
It comes as eight people are missing and presumed dead, with their bodies still lying on Whakaari/White Island, following its volcanic eruption on Monday while 47 tourists were visiting.
Twenty-three people injured in the blast were still being treated in hospitals around New Zealand, while a further five patients had now been transferred to Australia for treatment.
Families of the dead and injured were now flying into New Zealand from around the globe, and Whakatāne Mayor Judy Turner acknowledged a growing sense of desperation among them for the bodies still on White Island to be recovered.
However, volcanologists from GeoNet said the island had a 40-60 per cent chance of erupting again within the next 24 hours.
"Highly volatile", it was now more active than at any other point within the past two years, with the next eruption threatening to be more violent.
Magma had risen below the surface and a future eruption could send it spewing along with hard projectiles and ash into the area where teams would be working to recover bodies, volcanologists said.
This area was about 300m from the shoreline and spread across 200sq m.
The bodies of victims were lying together in small groups.
Clement said he could not give recovery teams the green light while conditions were so dangerous.
But police may consider seeking consent from the families of victims to instead launch a high-speed recovery operation in the future.
A normal recovery operation would include police spending enough time at the scene to collect the evidence needed to ensure all bodies were properly identified.
A fast mission, on the other hand, might not be able to achieve this.
"If you are the next of kin and we don't get an identification as a consequence of taking that process, they are not going to be happy and I would understand that and so would you," Clement said.
As a result, police may consider the possibility of going to the next of kin for their consent for a high-speed mission to be launched, should that be deemed the best option available, he said.
Clement said he would run through a range of recovery options with his inter-agency team at midday today.