Police say fires at two buildings overnight at Whakapapa skifield on Mt Ruapheu are suspicious.
A shed housing a snow groomer and the Knoll Ridge Cafe were well alight when a number of people reported an orange glow in the sky shortly after midnight.
The Fire Service was unable to reach the fires with vehicles because of their remote location - 1km from the end of the road.
A helicopter flew in a fire crew and an investigation team on Saturday.
