Documents show Māori are unsuccessful at nearly twice the rate of Pākehā at getting Covid-19 income support from Work and Income.
The Covid Income Relief Payment - which starts at $450 a week - is about twice the jobseeker support benefit, and Māori are much less likely to get it.
The Ministry of Social Development (MSD) information between 8 June and 28 August shows applications by those who identify as Māori were unsuccessful at nearly twice the rate compared to New Zealand Europeans.
More than a quarter of the more than 5000 unsuccessful applications were by Māori, despite them making up just 17.25 percent of the total lodged.
Applications by Pacific people were also less likely to succeed.
AUT law school director of Māori and Pacific advancement Khylee Quince said beneficiary advocates warned early on the new benefit would have unfair outcomes.
"Unfortunately poor brown people got the rough end of the stick.
"There's a reason that the payment was called the 'double dole' or the 'Karen dole' by many ... because ... it just so happens that it ... attempted to maintain the income of Pākehā middle class New Zealanders."
She said it was an example of unintended, systemic racism.
"This is just a continuation of long-term government policies that have continued to ignore the very racially and ethnically biased outcomes of welfare policies basically since the early 1990s."
The Ministry for Social Development said nearly 466 or 8.5 percent of the more than 5423 applications counted as being unsuccessful went on to get more money on the main benefit.
It said staff have no discretion over whether the 12-week payment is granted - people are either eligible, or they're not.
Disqualifying criteria include still being in part-time work - or losing your job for reasons other than Covid-19.
Beneficiary advocate Kay Brereton said she suspected a cause of the disparity was that Māori and Pacifika people were more likely to be working part-time.
She said the ethnic disparity was also likely a consequence of policy tunnel vision by Pākehā bureaucrats.
"The Covid Income Relief Payment is a really good example of people working within their own cultural paradigm where their reality is them and their friends have one job, they do it full time and if they lost it the world would be a terrible place.
"But not recognising that a lot of other people are in a different paradigm where they have two or three jobs and just losing one of them makes the world a terrible place because that'll be the one that puts food on the table."
Brereton said the Covid income relief legislation was drafted hastily under emergency conditions.
She said MSD needed to take the time now to analyse the stats so history did not repeat.
"Let's say that in the future we have another Covid lockdown, or we have some other incident that crashes jobs like this one has, and they need to design a [similar payment].
"If they haven't been able to collect the data to evaluate this one properly and to see why ethnic disparities exist, then there's a really good chance the same is going to happen again."
Race Relations Commissioner Meng Foon said sometimes rushed policy did more harm than good.
"The disparities are causing injustice and a breach of human rights to the Pacifica and Māori communities."
Foon said he wanted all the parties to get together as soon as possible to sort it out.
"I'd love to see the [Minister for Social Development] and [the ministry] and other associated organisations come around the table and talk to iwi, and talk to Pacifika in terms of how we can all do better.
Social Development Minister Carmel Sepuloni said she had asked MSD to analyse a sample of declined applications "so that we can better understand this discrepancy.
"This sample will include people who chose not to complete the CIRP application because they may have been better off receiving other support."
MSD said in a statement the reasons applications were unsuccessful was based on individual circumstances.
It said it has proactively contacted more than 30,000 clients who may be eligible for the Covid income payment.
Applications for the payment closes on 13 November.