Aerial reconnaissance missions have flown over Whakaari / White Island since the eruption on Monday afternoon and there are no signs of any survivors, police say.
The flights have been conducted by the police Eagle helicopter, rescue helicopter, and NZDF aircraft.
"No signs of life have been seen at any point," police said in a statement released at 12.11am on Tuesday.
"Police believe that anyone who could have been taken from the island alive was rescued at the time of the evacuation.
"Based on the information we have, we do not believe there are any survivors on the island.
"Police is working urgently to confirm the exact number of those who have died, further to the five confirmed deceased already."
Former Whakatāne mayor Tony Bonne earlier confirmed a local man was among the dead.
Eighteen others have been rescued from the island.
Both New Zealanders and overseas tourists are believed to involved, and a number were from the Ovation of the Seas cruise ship.
Police said as part of the recovery a NZDF ship would approach the island at first light to deploy drones and observational equipment to further assess the environment.
The Police Disaster Identification (DVI) team are assembling in Whakatāne to await deployment.
Deputy Commissioner John Tims confirmed the five deaths about 9pm on Monday and said it was too early to confirm nationalities but both New Zealanders and overseas tourists were involved.
Up to 50 people were believed to be on or around the island at the time of the eruption.