An independent inquiry has found child abuse and family violence amongst Maori is costing the country up to $3.4 billion.
Sir Owen Glenn's report looks at the amount paid for treating victims, loss of workplace activity and by government agencies this year.
The project commissioned by the Glenn Inquiry said tangata whenua are over-represented in statistics on child abuse and violence between intimate partners.
It said while Maori made up only 15 percent of the population, half of those who use Women's Refuge services are Maori, and over half of the number of family violence offenders.
So far in 2014, the cost of abuse amongst Maori is between $1.8 billion and $3.4 billion.
The report said there is general consensus that this due to the impact of cultural disenfranchisement, and more research is needed to understand the long-term effects of colonisation, alienation and the modern deprivation of Maori culture.