The 18-year-old killed in an early morning arson attack on a Greymouth house on Saturday was local man Karl Daniel Watson.
Police have launched a homicide investigation into the fire which destroyed the 100-year-old house and 15 police from Greymouth, Nelson, Westport and Christchurch are working on the case.
The body of Mr Watson was formally identified today, with fingerprints used because a visual identification was impossible.
Five other people, aged in their 20s and 30s, were in the house at the time of the fire and Detective Sergeant Kevin Tiernan, of Greymouth, said it was amazing police were not dealing with multiple deaths.
"A guy who was asleep in the house - his cap started burning. There was a woman in the house who had the hair on her arms singed and her pants started burning as she was running around trying to put the fire out."
Neither required medical attention.
Three separate attempts were made to start the fire.
Mr Tiernan said while it didn't appear accelerants were used, police were not ruling out the possibility.
Police were interviewing the other occupants of the house and a "large number" of their associates who were frequent visitors.
Mr Tiernan said it had been a slow day of progress in the case.
A specialist police arson investigator from Christchurch had joined the investigation team.