Ashley Bloomfield has revealed he had moments of self-doubt when advising whether New Zealand should go into lockdown back in March.
The Director-General of Health said he looked at how the virus was tracking around the world and had to weigh-up the "gamble" for locking down the country by using what was considered as incomplete evidence at the time.
New Zealand entered an alert level 4 lockdown on March 25 following days of case numbers steadily growing. At this stage, 205 cases had been confirmed in the country.
But Dr Bloomfield - who appeared on Newshub journalist Patrick Gower's coronavirus documentary On Lockdown, which aired on Three on Monday night - said it was a calculated gamble to put New Zealand into lockdown.
"You have moments of self-doubt. You think 'is this the right call'," he said.
"It is a gamble, however we could see what the alternative was... It seemed to us really clear [that] you either went into lockdown early and avoided a catastrophe, or the catastrophe was upon you and you still had to go into lockdown."
He said he was worried about the impact COVID-19 could have on New Zealand, because he was seeing a "triple whammy" of the virus' destruction overseas.
"First of all, the health impact and the deaths if it got out of control. The second was this huge impact on the healthcare system, but the third thing was just the impact on the social and economic wellbeing of the country."
Dr Bloomfield said the worry stemmed from knowing the virus could spread widely.
"The signs [were] that it was going to be kind of a big one, and there were moments where you think 'gosh, I wish this wasn't happening', but it is."
Just days before the country went into lockdown, he was in Invercargill for the New Zealand Pipe Band Championships, of which his son was a part of.
While he was there, he read "quite a seminal paper" which pulled together what was happening with the virus around the world.
"I can remember pacing around the room quite agitated. I just had this sense [saying] let's just push the button now, let's get ready."
The following day on March 14, the Government announced everyone that was arriving into the country was required to self-isolate for 14 days.
Watch the excerpt from Patrick Gower: On Lockdown.
