The family of Adelaide man Gavin Dallow say New Zealand police have found and identified his body following Monday's volcano disaster on White Island.

Key points: Lisa Dallow was found alive yesterday at a hospital in Hamilton, New Zealand

Lisa Dallow was found alive yesterday at a hospital in Hamilton, New Zealand Her husband and daughter are still missing after Monday's White Island volcanic eruption

Her husband and daughter are still missing after Monday's White Island volcanic eruption Her sister-in-law said the family was in shock after hearing the news

His stepdaughter Zoe Hosking, 15, is presumed to have died in the eruption which also claimed the lives of several others, including Brisbane woman Julie Richards, 47, and her daughter Jessica Richards, 20.

Mr Dallow, his wife Lisa and her daughter Zoe were declared missing after the eruption on New Zealand's White Island on Monday.

Ms Dallow was found alive in a hospital in Hamilton yesterday with critical burns to more than half of her body.

The Dallow family confirmed the tragic developments a short time ago.

"Gavin was a wonderful son and brother. We'll miss him at the cricket and we'll miss him at the football. He was a generous man, always helping his family and his community," the family said in a statement.

"New Zealand police have also advised the family that Zoe Hosking is presumed dead, with her body on White Island. Recovery may not be possible for at least a couple of days due to the dangerous conditions.

"Our hearts break at the loss of Zoe at such a young age. We know her loss will also devastate her school community and the local Girl Guides, of which she was an active member."

Gavin and Lisa Dallow on their wedding day in 2017. ( Facebook: Rotary Adelaide )

Mr Dallow's father Brian said his son's body was in Auckland and a post-mortem would be carried out before his remains were flown back to Australia.

He said he saw his son shortly before he left on his overseas trip.

"I was lucky enough to spend the last three days of the last Test match [at Adelaide Oval] with him, which was only two days prior to when he left," he said.

"That is something I'll hold in my memory for a long time.

"Just coming on Christmas, we're really going to miss him."

Mr Dallow said if his son had been advised about a potential risk "he wouldn't have gone".

"I'm pretty well sure they weren't fully informed of the dangers, otherwise he wouldn't have gone," he said.

School expresses sorrow for death of young student

Gavin Dallow ran his own law firm, while his stepdaughter attended St Aloysius College, which has also released a statement.

"We have spoken with Zoe and Lisa's family over these days, sharing their deep concern and grief," principal Paddy McEvoy said.

"The family's pain and that of their friends and the school community are beyond words, yet we cherish all that we have shared with Zoe."

Ms Dallow's brother, David Francis, has flown from Melbourne to be beside her in hospital.

Zoe Hosking is a Year 9 student at Adelaide's St Aloysius College. ( Facebook )

Earlier, her sister-in-law Meredith Dallow said she remained in a critical condition with severe burns.

"It's horrible being back here but then I think there's nothing probably we can do over there either," she said.

"We're probably better just staying put here until we get some more up-to-date information."

She heard about the explosion on the TV news and then called the New Zealand consulate to find out more.

The consulate confirmed the victims were from the Dallows' cruise ship Ovation of the Seas, and that the family had gone on a daytrip to White Island.

"I think we were just in shock and didn't really know what to think or do because at that stage I didn't know how bad things were or anything," Meredith Dallow said.

Tragic end to 'holiday of a lifetime'

Mr Dallow recently retired after working for a decade with the Legal Services Commission of South Australia.

Gavin Dallow had recently started his own legal firm, Dallow Legal. ( Supplied )

The commission's access services manager, Chris Boundy, said Mr Dallow had quit to spend more time with the love of his life and her daughter.

"He was a very giving, very generous and very loyal partner and I think they would have been inseparable," he said.

"From the sounds of things this was the holiday of a lifetime."

Mr Boundy said a workplace Christmas lunch yesterday was subdued.

"It was a very sombre affair — it was very bittersweet," he said.

"We almost feel guilty having a Christmas lunch today without Gavin's presence because he was a larger than life character."