Justice advisor Julia Whaipooti said it meant the system changes were not working for Māori.
"It shows that whilst it's working for young people, it's a strategy that is bringing down the numbers of young people coming into the system clearly without an intention and strategy to address young Māori, it's not going to get equal outcomes - that is something true across the whole justice system not just the youth justice system."
Haumaha convinced Te Pae Oranga a 'game changer'
One of the police strategies in bringing down these numbers is The Turning of the Tide, developed by iwi and police focussing on prevention rather than enforcement.
It has been in place since 2012 and aims to address the over-representation of Māori in the criminal justice system.
One of its key goals is to see a 10 per cent decrease in the proportion of first-time youth and adult offenders who are Māori.
Another is Te Pae Oranga, which is when after someone is arrested, police can refer them to an iwi community panel to be heard. The process aims to repair the harm caused by the offending promptly by using restorative community panel processes.
About 13 have been launched with a plan to increase that number this year.
Police deputy commissioner Wally Haumaha, who is also head of the Māori, Pacific and Ethnic Services division, said that he was determined to change the numbers.
"I am convinced in all my 35 years of policing that Te Pae Oranga is the gateway and game changer that is going to turn some of these statistics around because it puts our people front and centre of that ownership model."
Hoani Waititi Marae in West Auckland facilitates Te Pae Oranga. Operations manager Shane White said the fact the numbers showed a widening gap was hōhā and disappointing.
And although he commended people in the police trying to change things - he said it was not enough and the right people were not being referred through kaupapa, such as Te Pae Oranga, for it to benefit tangata whenua.
"Even with these beautiful high-level, cultural and indigenised approaches coming back down to the grass roots, on the street late night in Otara and Ranui, Māori people aren't getting that option, they still have the same option, this is becoming a well traversed path and it's sad to see that new police coming in are still following that practice."
Haumaha said in 2014 he appointed 12 Māori inspectors across the policing districts - he said that implementing the strategies from the top to the community is something they do have to strengthen.
"Those inspectors will take those strategies and will implement around their district leadership teams so they are the champions in the districts. We set the direction at the national level and they deliver the service on the ground floor and we have to get much sharper at doing that."
Māori communities mistrust police - justice advisor
White said a huge shift in culture was needed.
"I think it's going to take more than one or two initiatives, I think it's about really some honest deep look at the bones of the police force and the criminal justice system and some of its thinking."
Unconscious bias and institutional racism have been attributed as one of the reasons why so many young Māori end up being over represented in arrests.
Whaipooti said it was to the police's credit that they had been actively trying to address the issue, but she said it was much bigger than that.
"But when you see numbers not shifting you know that it is a structural issue and they are working within a structure that comes from a basis of racist policies and legislation and although they are trying to change the way in which they are trying to address Māori communities, which is really important, but we need to see a shift for the outcomes for Māori."
Whaipooti was an advisor of the He Waka Roimata report released in June by the Safe and Effective Justice advisory group, she said in that mahi she found the mistrust in the police was right across the motu.
"What we heard in Waka Roimata was that was happening 30 years ago and it is the mistrust that exists now in Māori communities from the north to the south."
Haumaha believed the police were moving in a better direction and if the statistics did not change then he said he and others at the top needed to be held accountable.
"If I don't see a down turn in those figures over the next 12 months we need to come back to the drawing board and ask ourselves and examine what that looks like - you mean sitting in our office here in Wellington or taking that multi-agency approach to sit at the heart of our people and let the people drive it and we just support it, that is where the game changer will come in."
- RNZ
