The Fire Service said last week that the blaze at La Carrière in Les Fonds des Longueville was started by an external source but declined to specify the exact cause.
Investigating officer Station Officer Trevor Frain is completing his report.
He said: ‘We know the fire developed in the south-east of the outbuilding from an external source and that was most likely to be a firework.’ The occupants of La Carrière, Emma O’Brien and Jim Boudin, and neighbours said at the time that fireworks were going off in the area from before 6 pm on Saturday 5 November into the early hours of the following day.
Ms O’Brien raised the alarm at 4.30 am.
