For the first time since last Monday’s White Island eruption, New Zealand authorities have admitted they might never find the remaining missing bodies.

On Wednesday afternoon, police declared their hurt from the unsuccessful retrieval missions for the bodies of Sydney teenager Winona Langford and local tour guide Hayden Marshall-Inman, saying they were “deeply sorry”.

Of the 47 adventure tourists and guides on Whakaari during the blast, all but Ms Langford and Mr Marshall-Inman have been accounted for.

Police have been positive and committed to returning bodies to families since establishing the retrieval operation.

But after two days of appalling weather this week hampering search efforts, and aerial surveillance seemingly ruling out the prospect of them returning to White Island, hopes are dimming.

“We are deeply sorry we haven’t until this time, been able to return these bodies,” deputy commissioner Mike Clement said.

“That has been our mission throughout. Firstly to save people and then to recover people.

“It hurts us. It hurts our people and it hurts everyone in the community when we don’t achieve that.”

The bodies of Ms Langford and Mr Marshall-Inman are thought to have lain near a stream that ran off White Island. Police say a 1.5-metre wave of water and sediment likely came down the stream, washing the bodies into the sea.

Bad weather on the night of December 10 is also believed to have contributed to the bodies moving further from the island.

Mr Clement said the stream had been searched three times, and aerial imagery has also confirmed the two bodies were no longer there.

“What we know is on the 11th of December there was a body of a male off the coast in the bay adjacent to the jetty and we believe that person to be Hayden [Marshall-]Inman,” he said.

“Despite our best efforts, we weren’t able to get [the body] before it went down again.”

He said the “very disappointed” recovery team got within metres of the body, but could not reach it.

Ms Langford’s body has not been seen since the deadly eruption.

Winona Langford. Photo: Facebook

On Tuesday, police expanded the search to include North Island bays up to 70 kilometres away, believing tides in the Bay of Plenty could have washed the bodies that far.

Mr Clement said authorities had scoured the eastern Bay of Plenty coastline.

Police said on Wednesday they were likely to downscale the body search in coming days.

“The reality is we’ve dived in the area where the body was last seen and we can’t find it,” Mr Clement told Radio NZ.

The heartbreaking scenario that the two bodies might never be found comes after the jubilation of last Friday, when a crack defence force squad retrieved six bodies from the island.

Mr Marshall-Inman’s family were in Whakatane for that mission, only to learn his wasn’t among the six bodies recovered.

His brother, Mark Inman, said the family was managing its grief as best it could.

“We’re coping. We’re staying positive. You’ve got to keep positive thoughts so that you can forever hope that he’ll return home one day,” he told NZ television.

“The only positive that would come out of him not returning is his absolutely love of the island and his passion for White Island.

“He’ll forever be a guardian out there.”

Mr Marshall-Inman had a long fascination with the volcano, with Mr Inman saying the fateful visit was his 1111th to the island.

“You could speak to him every day about it and he’d give you a new fact or something new that had happened on the island,” he said.

“He loved sharing such a beautiful place with so many people, both Kiwis and internationals.”

Ms Langford’s mother and father died in the explosion. Her brother, Jesse, is in hospital.

White Island tragedy: Confirmed dead

1. Krystal Eve Browitt, 21, Melbourne
2. Tīpene James Te Rangi Ataahua Maangi, 24, New Zealander
3. Zoe Ella Hosking, 15, Adelaide
4. Gavin Brian Dallow, 53, Adelaide
5. Anthony James Langford, 51, Sydney
6. Kristine Elizabeth Langford, 45, Sydney.
7. Matthew Robert Hollander, 13, US citizen, Australian permanent resident, Sydney
8. Berend “Ben” Lawrence Hollander, 16, US citizen, Australian permanent resident, Sydney
9. Martin Berend Hollander, 48, Sydney
10. Barbara Jean Hollander, 49, US citizen, Australian permanent resident, Sydney
11. Karla Michelle Mathews, 32, Coffs Harbour
12. Jason David Griffiths, 33, Coffs Harbour
13. 13. Richard “Rick” Aaron Elzer, 32, Coffs Harbour
14. Jessica Richards, 20, Brisbane
15. Julie Richards, 47, Brisbane
16. Australian man who died in a Sydney hospital on December 14. Family has requested his details not be released.

Missing, presumed dead:

1. Winona Jane Langford, 17, Sydney
2. Hayden Bryan Marshall-Inman, 40, Whakatane

-with AAP