Firefighters have been kept busy on Mount Ruapehu, after one of Saturday morning's suspicious fires on Whakapapa ski field flared up again.
Two buildings and large machinery was destroyed by the fires, which began around midnight.
The damage bill is estimated to be at at least $4 million.
Kim Perks of Central District Police says one of the fires has had a second life.
He says a scene examination will need to be performed before they can conclusively say the fires were deliberately set.
Ruapehu Alpine Lift general manager Dave Mazey says all that now remains of a chalet which housed the Knoll Ridge cafe is twisted metal and a slab of concrete.
He says it's the same story for a nearby building which housed three snow groomers, fuel and other ski equipment.
A building housing the chairlift was also on fire, but damage was limited. The lifts are being checked.
Mr Mazey says the winter operation will still start in June but the chalet may not be rebuilt for the 2009 season.
He says there is no vehicle access to the site which takes an hour and a half to reach on foot plus a long climb up to the buildings.
RAL runs the Whakapapa and Turoa ski fields.