The country's largest public health team has revealed it would take an entire day for it to dig Covid-19 case information from its systems that other regional teams were able to provide within hours.
Auckland Regional Public Health has declined to provide the information about its cases from clusters outside the region - a decision it took a month to explain.
The Herald first asked for the data on April 6, to use as part of a story about how clusters had spread around the country.
It also asked about their own clusters, and whether the index patient (the first person to get the virus) and the mode of transmission (if they got it locally or overseas) had been identified.
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Information provided by other district health boards showed how cluster cases - at that point the country's biggest Covid-19 threat - had crept from Auckland as far as Waikato, and from Invercargill to Wellington.
It highlighted the need for the ban on domestic travel, and the necessity of rapid contact tracing - at that stage still very much in the development stage.
Auckland Regional Public Health - which encompasses the Auckland, Counties Manukau and Waitemata District Health Boards - was one of only two services to refuse to provide information. The other was Bay of Plenty District Health Board.
Following a complaint to the ombudsman - the body which oversees the laws around public data - Bay of Plenty said it was concerned that providing such information would reduce its contact tracing ability.
"I acknowledge that the reason given for refusing your request may not have been clear," a spokeswoman said. "I am however satisfied that there were grounds for withholding the information given the small number of people involved and the real risk, at the time, that the release of this information would compromise the team's ability to identify Covid cases and trace their contacts."
It later clarified by phone that it had just three cases linked to clusters outside the region, and was worried those people might have been easy to identify.
It said contact tracing relied on trust between public health staff and those infected - in that they needed people to tell them exactly who they'd seen and where they'd been.
In some cases - for example if someone had cheated on their partner in a one-night-stand - patients could be very concerned about telling the truth, it said.
The Herald has asked the ombudsman to continue to look at those refusal grounds, given other health boards did not have the same concerns.
Auckland District Health Board, which replied on behalf of the public health service via its lawyer Bruce Northey last week, had different grounds for declining the request.
It said the reason it wasn't providing the information was because its intelligence team said it would "take one working day" for someone in Auckland to pull the data about cluster cases and where they came from.
"We therefore decline to provide this information, as these staff are committed to assisting with the Covid-19 response," it said.
However, given other health boards were able to find that information quickly, it raises more concerns about Auckland's capability - which the Herald has put back to the DHB.
Auckland did provide some further information about its own cluster cases - saying it was yet to identify the origin of transmission to the index case in some clusters.
It also clarified that the origin of transmission was "person-to-person".
The Herald has asked the ombudsman to continue to investigate the issue.
The complaint initially also focused on the Ministry of Health's refusal to name two clusters in Auckland, but it later changed its mind and named them as a private stag party and a cluster originating at disability service Spectrum Care. Officials later clarified this, saying the second cluster originated in the community and subsequently led to an infection of a person linked to Spectrum Care.