The Government was mostly flying blind on how essential workers were being protected during the alert level 4 lockdown or whether people with Covid-19, or suspected of having Covid-19, were properly keeping to themselves.
A report from the All of Government team, dated April 15, also found that one-third of Kiwis felt that the lockdown didn't go far enough, opening up the possibility of tougher measures to be rolled out if necessary.
This was the first weekly monitoring report into the lockdown that was used to inform Cabinet about decisions to move between alert levels.
It noted that the number of daily cases at the time had been flattening for a week, and there were signs that there was no community transmission of Covid-19.
But the paper also noted that there were gaps in the data that had the potential to undermine confidence, including a lack of end-to-end data that could show how much time it took from the onset of any symptoms until contacts had been traced and isolated.
That data has only just been published by the Ministry of Health for the first time two days ago - more than three weeks after the report.
The weekly report added that there were gaps in the ministry's data.
"A significant number of cases have missing information and some others have been under investigation for a long time. This somewhat reduces our confidence in the data on community transmission."
The paper said that stopping the spread of Covid-19 relied on people with the virus, or suspected cases, to stay isolated - but there was no monitoring of whether this was occurring.
"We currently have little understanding of compliance with that self-isolation."
Nor was there widespread understanding of how businesses were protecting 529,000 essential workers under alert level 4.
The Ministry for Primary Industries had made 2730 on-site checks and 2401 remote checks, and issued nine warning notices, but beyond these checks there was "limited information".
"We do not have data on whether other essential workplaces have robust plans and processes in place."
Independent surveys showed that there was strong support for the lockdown, the paper said, including a "significant proportion" believing that it should be extended.
"The majority consider the measures imposed are about right, but a third think they do not go far enough. This may indicate some appetite for measures to be strengthened if necessary."
The paper also noted the deferring of health services to create capacity for Covid-19, and there was a "substantial risk of latent demand for health services which may translate into actual demand" at a lower alert level.
It also noted how alert level 4 had exacerbated issues for Māori and Pacific Island communities, as well as disabled people.
"Disabled people and older people are reporting concerns about limited access to services, disruption to services (including disruption due to limited access to PPE for those providing personal care) and concerns about accessing food and other vital supplies.
"This could lead to an increase in demand for aged care facilities, the paper said.
"Māori and Pacific island communities report pre-existing concerns made worse by the Covid-19 situation, including poverty, disruption to seasonal employment, digital exclusion and increased family violence under alert level 4 restrictions.
"There are also reports of a reluctance to seek testing for Covid-19 owing to fears about missing work while self-isolating."