Ten Australian volcano victims 'critical'

Two NSW residents who arrived overnight at Sydney's Royal North Shore hospital are among seven across the city's hospitals listed as critical.

Two other NSW victims are stable while another's family has requested privacy.

Three patients evacuated from New Zealand to The Alfred hospital in Melbourne are also critically ill.

Some 47 people, including 24 Australian citizens and four permanent residents, were on the island when the volcano erupted on Monday.

Nine Australians are confirmed dead, two are presumed to have died and 13 are in hospital with severe burns.

However that may change, with NZ police confirming on Saturday evening another victim of the blast had died in hospital, without offering further details.

Brisbane woman Julie Richards and her university student daughter Jessica; Coffs Harbour couple Richard Elzer and Karla Matthews; Melbourne woman Krystal Browitt and Adelaide schoolgirl Zoe Hosking, 15, are all believed to have perished when heat, ash and toxic gases enveloped the island following the eruption.

Ms Browitt was enrolled in La Trobe University's Bachelor of Veterinary Nursing degree run via Melbourne Polytechnic, the institution confirmed on Saturday.

"Our thoughts are with her immediate family and we also extend our heartfelt condolences to all of Krystal's family and friends at this very difficult time," the university said in a statement on Saturday after NZ police confirmed her death.

Sydney's Hollander brothers Berend, 16, and Matthew, 13, and Coffs Harbour man Jason Griffiths died in hospital from their burns, while Adelaide man Gavin Dallow, 53, was declared dead on Wednesday.

Fears are held for Berend and Matthew's parents Martin and Barbara Hollander, while Sydney couple Anthony and Kristine Langford and their daughter Winona, 17, are missing.

Extended family have indicated the Langfords' son Jesse, 19, survived. He's likely among those being treated in Sydney.

Australian Associated Press