There's evidence the Port Hills wildfire could be the result of an arson attack, according to Prime Minister Bill English.
Mr English cancelled a full schedule of events to travel to Christchurch and tour the fire grounds with Civil Defence Minister Gerry Brownlee today.
"I've only had a very brief description of the fire starting in two places at about the same time which, to someone like me, looks a bit suspicious," Mr English said after viewing the area from a helicopter.
"I wouldn't want to jump to conclusions but that seems a bit odd."
Investigations are still underway to confirm the cause of the blaze which has destroyed 11 home and outbuildings, spreading across more than 2000 hectares since Monday.
Mr English met with a number of firefighters who have been battling the blaze and say while they look tired they were confident in their training and teamwork.
Mr Brownlee praised those on the ground for their efforts and the huge amount of "goodwill" that came from them giving up their time and putting their lives on the line.
His visit came a day after he questioned the emergency response to the blaze, including why a state of emergency wasn't called sooner.
"I think the most accurate advice I was getting yesterday came from the media," he said today.
He didn't lay blame on the rural fire services, firefighters or volunteers who who were in charge of the blaze at the time, rather said it was a legislative issue.
"I don't want any suggestion out there from me that they've been doing anything other than an amazing job. These are very brave people doing a great job, there's no question about that," he said.
"It's structures inside the legislative arrangements that fall to politicians to fix and we've got to fix it."
Labour says Mr Brownlee should have called a state of emergency himself, allowing fire services to commandeer resources as soon as they were needed.
He agreed that was true, but said doing so required full knowledge of the scene, and there are structures in place for those with that information to make the decision that need to be fixed in future.
Representatives from all parties are set to come together for a meeting at Parliament today to begin discussing how to improve those structures, he said.
Containing and controlling the fire could take days or a week and going back through the process is something for another day, Mr English said.
"What's important now is the ongoing containment, hope that the weather stays right and that the people who are affected have the support of the community because some of them have lost their houses and their life savings," he said.
Residents of upwards of 450 homes have been evacuated as the fire continues to burn. There's no timeline for when it will be safe for them to return.
More than 130 firefighters, 45 tankers, 15 helicopters and dozens of Defence Force and police staff have joined battle to control the blaze.
Crews on board the US Coastguard ship Polar Star have also been assisting, Mr English revealed.
Their help follows the assistance of crews on board USS Sampson following the Kaikoura earthquake in November.
Offers of help from Australian firefighters are also being considered.
Mr English is due to meet with Australian Prime Minister Malcolm Turnbull in Queenstown tomorrow where he will raise what he described as a "great example of Trans-Tasman co-operation".
"I will be thanking the Prime Minister for the offers and indicating that if we do see a need for it then we will take those offers up and we appreciate the generosity of the Australians," he said.