New claims before the Waitangi Tribunal argue colonisation is partly responsible for the high suicide rate among Maori.

The hearings will see families of those who have taken their lives tell the tribunal how the modern-day loss of life stemmed from broken promises made at the time of the signing of the Treaty of Waitangi.

Among those people taking claims is Jane Stevens, whose son Nicky took his own life in March 2015.

"Colonisation is not just something that happened in 1840. That taniwha is with us today," she told the Weekend Herald.

"For me, this is focused on my son's story but it is also many people's stories."

Stevens was schizophrenic and receiving mental health care in Hamilton under a compulsory care order. He failed to return from an unsupervised smoke break in March 2015. His body was found in the Waikato River a few days later.

The tribunal has accepted five claims, including Stevens', in recent months as it began to usher in a new generation of hearings around grievances based on losses other than land.

The next phase is the kaupapa series of claims - 11broader issues on which the tribunal has agreed to hear evidence around Maori rights.

It is the "health services" kaupapa hearings that have attracted claims around suicide.

A timetable has yet to be set for the hearings but they are likely to start next year.

The suicide rate for Maori last year was 21.7 deaths per 100,000 people - double that for Pasifika communities and higher than the 14.6/100,000 recorded for people of European descent.

In some demographics, Maori were a clean statistical sweep. Last year, all girls aged 10-14 who took their lives were Maori.

Stevens claim over her son's death was accepted by Judge Patrick Savage, who said the claim was "contemporary in nature and national in scope".

She told the Weekend Herald that mental health statistics showed a clear difference between issues afflicting Maori and those impacting on others in society.

Stevens said she was taking the claim partly to honour her son and to try to meet the responsibility she had while he was alive.

"As a mother that was my job - to try and keep him safe. I certainly felt I wasn't able to do that no matter how hard I tried."

Stevens said one aspect of change she sought was to make family an integral part of dealing with mental health. Currently many felt excluded with the system struggling to balance its duty to an adult patient against a family's desire to be involved.

For many Maori families, she said suicide was a constant. In her whanau, her father Ron had attempted to take his life, she had attempted to take her life twice and her son managed to do so while in mental health care.

Recent comments about te reo by former National Party leader Dr Don Brash and the Treaty by Sir William Gallagher left her "gobsmacked" at the "arrogance and self-righteousness of their positions".

But Stevens said that as someone who was Maori but appeared Pakeha, she often heard adverse comments "about Maori moaning again".

"Skin colour doesn't change the impact of colonisation."

As a result, she knew the issue of colonisation would be difficult to raise because there was a "cringe factor in talking about these things".

Nicky Stevens took his life in March 2015.

"Mainstream society in New Zealand has been very good at ignoring what's happening to Maori for some time."

Others claims have also been lodged, including by Otago University academic Dr Keri Lawson-Te Aho, who is organising an international symposium in Wellington next year on indigenous suicide.

Lawson-Te Aho's doctorate research published in 2013 defined "historical trauma".

"The seed that grew to become historical trauma was planted at the time of colonisation," Lawson-Te Aho said.

The claims assert failure on the Crown historically or on the Government as recently as this year.

One claim pointed to former Health Minister Dr Jonathan Coleman's reluctance to fix a target for reducing suicide in case the Government was blamed for not achieving the hoped-for result.

Lawyer Gerald Sharrock said such accountability went to the heart of the Government's duty to the people. He lodged the claim on behalf of clients in Te Tai Tokerau, where Maori youth had featured distinctly in recent suicide statistics.

On colonisation and lasting effects, Sharrock said: "There is no doubt. First nations people in the Australia, the United States and Canada all have similar issues with suicide - and family breakdown, family violence and substance abuse."

The former Minister of Maori Affairs, Te Ururoa Flavell, said there was solid research to support claims of ongoing harm from colonisation. The research had been done across a number of nations which had previously been colonies and had shown similar impacts on the indigenous peoples living in those countries, he said.

He said there might be resistance to the idea - as there was when the national anthem was first sung in te reo.

"It's just part of us moving forward as a nation," he said. "Actually, we're addressing a wrong - it's not just a big handout for Maori. "

Suicide prevention campaigner Mike King said identifying colonisation as a factor did little to protect young people now.

"Of course there's a connection. But all this shit about teaching your kid a pepeha and to do one haka and one song - these kids turn up at a marae and they still feel stupid."

King said trying to apply tikanga solutions to children raised out of traditional Maori society made little difference.

Meanwhile, he said the focus on the high Maori suicide rate had "created a conversation among white New Zealanders" that some children were more important than others.

The tribunal has no power to order changes but does make recommendations to government. Stevens has sought improved funding of tikanga Maori health services and greater consultation with Maori.

The issue of colonisation was most recently raised by health minister Dr David Clark during an interview with the NZ Herald. He said reasons for New Zealand's world-leading suicide rate included "communities that are experiencing hardship or the after-effects of colonisation or trauma in their own lives or personal histories".

The statement has created a political hot potato, with Opposition MPs quizzing Clark in Parliament, attempting to have him expand on his answer.

Clark has not done so in Parliament and has refused Weekend Herald interviews to expand on the comment.

The National Party has also done all it can to avoid being interviewed on the issue. Numerous requests to health spokesman Coleman went without response.

Then numerous requests to National's mental health spokesman, Matt Doocey, went ignored.

Media staff in the National Party leader's office said he was happy to be interviewed on mental health but not when questions of colonisation were included.

YesWeCare health coalition co-ordinator Simon Oosterman said colonisation was a difficult issue for many to debate but there was clear evidence of the need to do so.

"When Maori are most at risk of suicide, it's hard to ignore colonisation. There's been a willingness to break the silence around suicide but if it's to be meaningful, they have to break the silence around colonisation."

The kaupapa claims
•Maori military veterans
•Health services and outcomes
•Constitution, self-government and electoral system
•Mana wahine and mana tane
•Education services and outcomes
•Identity and culture
•Natural resources and environmental management
•Social services, social development and housing
•Economic development
•Justice system
•Citizenship rights and equality