Mr Vosu said eyewitnesses had reported seeing an orange glow before the fireworks bursts, the reports being consistent with the theory of an external fire outside the fireworks storage magazine, leading to the explosion.

He said the WorkCover investigation looked at possible causes of the external fire.

Mr Vosu said although there was significant storm activity in the area on the night of the explosion, there was no evidence of lightning strike and also it was highly unlikely the fireworks storage caused the fire. He said they also investigated whether dew inside the storage magazine could have caused chemical activity leading to the combustion of the fireworks but given the evidence gathered, it is most likely the fire was external to the magazine.

He said it was also possibile that someone could have started a fire on the site. “Foul play is something I can’t discard entirely.”

He was asked how someone could have started a fire on the site, with Mr Vosu replying that remote devices, mechanical devices and electronic timers, even a candle could burn down to a point, setting of a fuse.

Mr Vosu told the inquiry that the investigation showed no evidence of a break-in.