Fire investigators were working yesterday to determine whether the blaze at The Bog Irish Bar was arson.
East Otago fire risk management officer Michael Harrison said the investigation to find the cause of the fire at the Dunedin bar continued yesterday.
The cause had not been determined and the possibility the fire was suspicious had not been discounted.
East Otago and Southland fire risk management officer Cathy Trevathan was investigating the fire and was working with private fire investigators, who were working on behalf of insurance companies.
''We can't rule it out at this stage ... they are not ruling out anything until they have a conclusive finding to how the fire started.''
On Sunday, firefighters were called and patrons were evacuated after an alarm activated at the bar, on the corner of London and George Sts, at 7pm.
Minutes later, flames ''erupted'' from three windows of an upstairs office, Dunedin City fire station senior station officer Jason Hill told the ODT on Sunday.
Mr Harrison said the investigation could take weeks or months.
