Northland Police have confirmed they're treating last month's fire on the Karikari Peninsula as arson.
They say any possible natural cause has been eliminated, and they now want to identify those responsible.
They want to hear from anyone who was in the Karikari Peninsula on the afternoon of November 30.
Pilot 'Prickles' de Ridder and DOC ranger William Macrae died during the fire, when their helicopter crashed as they tried to assist those caught in the blaze.
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