The blaze broke out on the top floor of Loafers Lodge hostel shortly after midnight on Tuesday.
Fire and Emergency New Zealand (FENZ) said the fire is being treated as suspicious, however police don’t believe it was deliberately lit.
“At this stage the fire is unexplained,” Acting District Commander for Wellington police Dion Bennett said in an update to media on Tuesday afternoon.
Authorities said they have been unable to search all areas of the building due to extensive damage.
Bennett said police will likely enter the building tomorrow between mid-morning and midday after a handover with FENZ.
“We know that there are a huge number of questions that people will have,” Bennett said, asking that people avoid speculation until the facts are known.
He urged anyone with information that could help determine who was in the building at the time of the incident to call the police non-emergency number, 105, and use Operation Rose as code word.
Chief Coroner Judge Anna Tutton said it has not been possible to recover the victims from the scene.
She said identification of the deceased would be a slow and complex process.
“We know that families will be desperate to have their loved ones back with them, we understand that, but we have to get it right,” she said.
“We can’t say how long the identification process will take, but I give my absolute assurance that we will work … as quickly as we can to reunite families.”
