The Ministry of Health is standing by its original decision not to release data around Māori vaccinations.
The Whānau Ora Commissioning Agency wants Māori NHI information so vaccine providers can directly contact unvaccinated Māori.
It took the ministry to court last month for refusing to hand over the data.
However, in a Friday letter to its CEO, John Tamihere, Director-General of Health Dr Ashley Bloomfield said: "In seeking to ascertain the Māori rights and interests that could be impacted by the disclosure of information for the entirety of Te Ika a Maui, and in light of the evidence of vaccine uptake and coverage, we have concluded that it would not be appropriate to adopt a blanket approach to the sharing of Māori health information you have requested on a North Island-wide basis."
Bloomfield said the ministry would work with the agency to identify rohe where vaccination outreach to Māori is most needed and then "identify the necessary and appropriate scope of data sharing in each case".
This decision comes despite High Court Judge Cheryl Gwyn instructing the ministry on Monday to reconsider its initial refusal.
She said the ministry's reasoning lacked rigour and it had failed to take into account its partnership obligations under Te Tiriti o Waitangi.
Tamihere is not happy, saying Bloomfield had effectively sentenced Māori to unchartered fishing expeditions.
"Every day delayed, is a day closer to Māori feeling the full brunt of the Covid-19 pandemic. We must have immediate access to that data so we can give our people an opportunity to be vaccinated and a chance," he said.
"We are now talking about a life and death situation. The life of vaccinated white New Zealanders and the deaths of brown unvaccinated New Zealanders.
"Arden must now take back control of Government from these unelected bureaucrats."
He dubbed Bloomfield the "Dictator-General of Health" over blocking the agency from "life-saving Māori data".
This puts poor communities and thousands of Māori at risk, Tamihere said.
He said his agency will now have to waste valuable time and resource appealing the ministry's decision.
As of November 4, 73 per cent of Māori have received their first dose and 55 per cent are fully vaccinated.