A specialist in social work is warning the Government's social bonds scheme will do nothing but harm to Māori and Pasifika mental health patients.
Through its social bonds, the Government will pay a return to investors, determined by whether or not agreed social targets have been achieved.
But an associate professor at Massey University's School of Social Work said it was a concern that the scheme had not been tested first.
Mark Henrickson said Māori and Pasifika accounted for nearly half of people with mental health disorders in New Zealand.
He said through social bonds, the New Zealand Government was proposing to carry out a large social experiment on already vulnerable and marginalised communities.
Mr Henrickson said if New Zealand wanted to be a world leader in effective and efficient mental health care, the Government needed to commit more resources where they would be most effective.
"There are some social bonds initiatives in the United Kingdom, in the United States and in some other English speaking countries around the world, but none of them have Māori and Pasifika populations," he said.
"Since nearly half of our mental health community in New Zealand is Māori and Pasifika, it would be very important that we don't conduct some kind of social experiment on them."
Mr Henrickson said he disagreed with the Government's money-focused approach to mental health.
"What's really happening here is the Government speaks the language of business and is attempting to engage business leaders around a social challenge.
"That simply isn't going to be a very effective way of responding to a social challenge," he said.
"Social workers, counsellors, nurses, psychologists, psychiatrists, physicians and other care and support staff work daily with clients to achieve small, barely measurable successes because they are committed to the work of caring - not financial profit."
Mr Henrickson said assisting mental health agencies to develop evaluation models, addressing stigma, incentivising employers and consulting with sector stakeholders about ways to improve services would be a better way to help.