Senior Sergeant Paula Enoka, of Queenstown, said some of the documents had partial names on them.
‘‘Police attended the scene, took photographs, seized evidence and warned nearby neighbours.''
She told the Otago Daily Times it was likely someone walked into the forest area, as ‘‘you couldn't throw something that far''.
Helicopters were turned back from the fire in the forested hills above Queenstown just after midnight.
Otago Rural Fire Authority deputy principal rural fire officer Jamie Cowan said, ‘‘The best Christmas present is that it didn't go anywhere''. Queenstown's fire crews were called to Fernhill's Bird Pl about 12.15am yesterday.
Senior Station Officer Dave Christie said: ‘‘We just got here and we saw flames up the side of the hill there.''
Three Queenstown fire units were helped by benign winds and relatively cool conditions.‘‘We had it knocked back within five minutes,'' Mr Christie said.
Fire crews were mobilised from as far away as Alexandra and Kingston.
Mr Cowan said helicopters were on the way when fire volunteers doused the blaze.
‘‘We believe the fire was a suspicious fire.
‘‘The Fire Service made a very good early save and managed to get it contained really quickly.''He said the fire was started near houses but never threatened them.
‘‘Our main risk from here is uphill to the [Skyline] gondola.''
The burnt area - which measures about 30sq m - was monitored overnight. Sgt Enoka confirmed police were speaking to those named in the documents found at the scene.
Additional reporting by Mandy Cooper.
