Police have revealed petrol was poured over the wall of an Auckland school boarding block where boys were sleeping moment before it was set on fire.
Pictures have been released of two men police believe can help with their investigation into the arson attack at Mt Albert Grammar School boarding house nearly six months ago.
This week police confirmed an accelerant was used to light the fire that saw teenage boys flee the burning building after midnight on November 25.
"During the incident petrol was poured against the wall of a boarding house and it was set alight. Thankfully nobody was injured as a result," they said.
They were now appealing to the community to identify two men, one who has his face partially obscured by a blue bandanna, that were captured on CCTV footage that night.
"We believe both of them can assist our investigation."
The School House hostel was left inhabitable after it was damaged in the late-night blaze, which police and fire investigators were treating as suspicious from the outset.
The fire broke out at the back of the school dormitory during a rain storm.
Sleeping teenage boys and staff were forced to flee the burning building in the middle of the night after they were awoken by alarms and the smell of smoke.
The school's board of trustees chairman Greg Moyle said the school surveillance equipment identified at least two people on the grounds, showing the arsonist was not working alone.
"We're hugely concerned someone could come from outside our school community on to our grounds and perpetrate this sort of act."
He reserved high praise for staff and pupils inside the burning building, saying thanks to the level-headed actions of those in the dormitory, a tragedy was averted.
"They acted incredibly professionally in how they dealt with the incident and as a board we're very appreciative of the staff there and proud of how the students reacted.
"This could have been horrific. As you can imagine, it's extremely concerning.
"We're incredibly lucky that it is a quiet time of the year and the boarding facility is not full. It could have been a lot more serious.
"Anything with fire has huge potential for massive damage and loss of life. We take the safety of students very seriously and this is one case where the safety of students was threatened," Mt Albert Grammar School headmaster Pat Drumm said.
Police said if anyone knew the two people caught on camera or had information to assist to contact them on 105 quoting the file number 201125/9901 or send a private message on Facebook.