A sixth person who was rescued from Whakaari/White Island on Monday died late on Tuesday in Middlemore Hospital.
Eight people are still missing and are presumed to have died on the island.
Forty-seven people were on the island when the volcano erupted - 30 are now in hospital and three have been discharged.
The Ministry of Health says of the 30 in hospital, most are in burns units in Christchurch, Hutt Valley, Waikato and Middlemore Hospitals.
Police will try to determine this morning whether it's safe to go back to Whakaari/White Island to retrieve the bodies of those killed in Monday afternoon's volcanic eruption.
Drones carrying specialist measuring equipment to collect and analyse gas levels will be deployed if the wind allows.
Police announced on Tuesday a criminal investigation into the disaster would be launched but later changed tack and said they were investigating on behalf of the Coroner.
Their inquiries will be done in parallel with a WorkSafe investigation.
Police Minister Stuart Nash speaks to Corin Dann.