The exact cause of a massive blaze at a property on Paradise Valley Rd in February might never be known - but any foul play or a purposely lit fire has been ruled out.
The fire broke out about 11pm on February 4 in sheds that were near a main house.
Neighbours on Paradise Valley Rd told the Rotorua Daily Post at the time they heard a massive explosion before seeing the large flames.
The sheds were rented by a local metal sculpture artist and car enthusiast who lived on the site and used the workshop space for his business.
He didn't want to comment to the Rotorua Daily Post but a Givealittle page was set up for him by a friend at the time of the fire that raised $6880.
The page said he was talented and renowned and the fire had meant a "world of dreams" had gone up in smoke. He had no insurance.
The Givealittle page said among the destruction was his 1964 RHD Chevy Impala convertible, Chevy Bel Air, Oldsmobile and a Vauxhall.
An incident report released under the Official Information Act said a scene examination conducted by a Fire and Emergency NZ specialist fire investigator showed several ignition sources. However, there was nothing conclusive and the cause was considered undetermined.
The report said there were two large garages at the property, one 6m by 10m and the other 10m by 15m.
The report said the artist left the property about 7.45pm on the night of the fire. Earlier, he had been welding on one of the vehicles and noticed a small smouldering fire in the upholstery.
He patted out the fire and put water on it to ensure it was out. All the windows were up in the vehicle and he could not see or smell any more smoke.
He stayed at the property for a couple of hours afterwards to ensure there was no more burning and checked on the vehicle again as he walked out the door.
When the fire investigator initially spoke to the artist he was upset and concerned the fire had started from a spark from the welding, but the fire investigator ruled this out.
The report said the fire patterns indicated the car was not the point of origin for the fire and there were several indicators within the vehicle which meant the fire hadn't started there, including that there was still visible upholstery, the glass pane was still in the window with just a crack through it and there was still paint on the body of the vehicle on the side where the spark was seen.
A cheap bedside lamp that was possibly left on was also ruled out as it didn't have enough fire damage.
The artist told the investigator there had been some electrical issues in the garage as the main fuse sometimes tripped when he used his welder.
The power distribution board was found and checked but not all of it, including the wiring, could be found. The report said therefore an electrical fault couldn't be discounted.
There was a lot of paint, thinners and other materials but no sign of any accelerants.
"There is no evidence at the conclusion of the scene examination that would determine that the fire has been deliberately lit," the report said.
There was also no evidence of unlawful activity, broken windows, damaged vehicles or fuel containers that were foreign to the property, it said.
The report said the cause of the fire was "undetermined".
"An unidentified electrical event is thought to be the most likely cause, however, it could not be established as the exact cause of the incident, given the fire damage," the report said.