Exclusive: Cause of massive Wanaka scrub fire that consumed 200 hectares of hill country finally revealed

The cause of the massive Wanaka fire, that consumed 200 hectares of hill country, has finally been revealed.

A two week long investigation by Fire and Emergency New Zealand has found it was caused by a local resident discarding ashes from their outdoor fire at the back of their property.

Regional manager Mike Grant says they'd cooled the ashes for three days, and tipped them out on gravel. When they saw they were smoking they hosed them down, but three days after that they became the ignition point for the fire that consumed 200 hectares of scrub.

He says they've done everything they thought they should, and what's happened is the extreme conditions we've been having have aided that fire to stay smouldering and get away.

He says they've been working closely with the property owners who started the blaze, and they've been hugely supportive, but "it's yet to be determined" if they will face repercussions.

A legislation change six months ago means they don't automatically face costs or a fine for starting the blaze accidentally.

The firefighting bill, has now hit the half million dollar mark, as eight helicopters and 40 ground crew were brought in to get the fire under control and protect numerous homes and two camping grounds in its path.

Principal rural fire officer Graeme Still says it's a reminder how careful people in Otago and Southland have to be in these extreme fire risk conditions.

He says they aren't even into the traditionally worst fire period yet that runs until the end of February.

"It's not the worst, but it's shaping up to be the worst. We need rain and we need it quick".

The blaze took hold behind the Central Otago resort town at the start of this month. Source: 1 NEWS