Halogen lights are being blamed for a fire that partly gutted a Suffolk factory that makes Branston pickle.
The pickle factory fire began near wooden pallets and gas cylinders
About 150 firefighters tackled the blaze at Premier Foods in Bury St Edmunds on Wednesday morning.
An investigation has found the most probable cause of the blaze was heat off the halogen lights, which then set fire to plastic packaging on bottles.
The bottles were stored on wooden pallets in a covered walkway, enabling the fire to spread quickly.
Fire crews spent over 24 hours at the factory getting the fire under control.
Officers are warning anyone with halogen lights to make sure there is enough space and ventilation around them.