"Our investigation is well advanced, evidence gathering and inquiries at the scene have been completed and a range of witnesses have been spoken to.
"These fires had a devastating impact on the Port Hills and wider community and we encourage anyone who has information that may help find the person responsible to come forward.
"Someone in the community will have information that is crucial to this investigation and we encourage you to make contact with us."
Fire and Emergency office of the chief executive director Leigh Deuchars asked that locals stay patient, as investigators couldn't say much now that the investigation was a criminal matter.
"We understand this may be frustrating for residents who are anxious to know more information about the fires.
"The investigation into the second Cause and Origin Fire Investigation Report is still ongoing and expected to take at least a couple of months.
"The immediate focus for Fire and Emergency New Zealand in the wake of the fires was on putting them out, ensuring the safety of the community and limiting the damage to property as much as possible.
"When a fire is suspicious, it becomes a criminal investigation managed by the Police.
"These investigations are taking some time to complete given the scale, damage and amount of information, some being very technical, that needs to be considered."
Anyone with information is asked to called Christchurch Police on 03 363 7400, or anonymously through CrimeStoppers on 0800 555 111.
The Port Hills fire burned through 2000ha of forestry and 11 homes, and required a large firefighting operation over several days to put it out.
Former SAS soldier and experienced pilot Steve Askin died trying to fight the flames, with a report showing cables from a monsoon bucket caused a fatal accident.
The cost of fighting it reached $7.9 million, including $2.1m for aircrafts costs alone.
