Key focus of Ruapehu arson inquiry

A key may unlock crucial evidence in the police investigation of a February arson attack at Mount Ruapehu that caused more than $10 million worth of damage.

The deliberately lit fires destroyed the Knoll Ridge Chalet, which housed a cafe and shops, a workshop and a chairlift building.

Police had found a key engraved with the numbers 474564, Taumarunui Detective Chris Chapman said.

"We aren't able to say too much about how we came by the key as it could jeopardise the investigation."

But it did relate to someone who had become a person of interest, Mr Chapman said.

"Identifying what it opens could greatly assist us in confirming his involvement or eliminating him from our inquiry," he said.

The key showed signs of reasonable use.

Police had been told that each number indicated the depth of the cuts of the key and that it was unusual for this number to be engraved onto the key itself, Mr Chapman said.

The key could be for a storage facility, bach or house possibly within the region of the Central North Island, he said.

- NZPA