A man accused of arson over the fatal fire at the Loafers Lodge hostel in Wellington has been charged with five counts of murder.
"The 48-year-old man already remanded in custody on two counts of arson is now also facing the additional charges," police Inspector Dion Bennett, the Acting Wellington District Commander, said on Thursday.
"The victims' families have been advised."
The fatal fire, which claimed the lives of five people, ripped through the hostel in the early hours of May 16, forcing some people to flee in their pyjamas.
Others were rescued by firefighters from the roof or dived from windows.
The alleged murderer also faces two counts of arson, one relating to a couch fire in the hostel and a second relating to the fatal fire that broke out two hours later.
Police allege that in the second fire the accused caused intentional or reckless damage to property when he knew that damage to life was also likely.
The arson charges alone carry a combined maximum sentence of 21 years in prison, while New Zealand law imposes a mandatory life sentence for murder, with a minimum non-parole period of at least 10 years, according to the New Zealand Law Commission.
Inspector Bennett said police had finished their "extensive scene examination" and would hand the scene at Loafers over to Fire and Emergency NZ (FNEZ).
"Once FENZ have completed their work, the site will then be handed to Wellington City Council and the building owner," Inspector Bennett said.
"Once the building is returned to the owner, we understand they plan to facilitate any return of personal property from the building in cases where rooms and items have not been destroyed or contaminated by fire."
He added that he hoped Wellington residents would welcome the upgraded charges.
The Loafers Lodge offered 92 basic rooms with shared lounges, kitchens and laundry facilities.
Some residents were placed there by government agencies, while others worked at a nearby hospital.
Emergency officials said the building had no fire sprinklers.
The man accused of murder and arson has been scheduled to return to court on June 19.