Public money has been poured in, but there has been no progress in efforts to combat family and sexual abuse, according to the Auditor General.
It has issued a report telling government ministers they need to talk to each other to make a joint venture on family and sexual violence work successfully.
In 2015, it was estimated the government spent more than $1.4 billion a year on the consequences of family violence.
But the Auditor General says the joint venture lacks clarity.
The audit lead on the report, Richard Towers, told Checkpoint ministers and agency staff need to do better.
"People talk a lot in Wellington about the siloed mentality of government protect that ministers and their agencies tend to work alone. The joint venture is supposed to be a remedy to that. But what we're saying is really a reversion to those old ways of working," he said.
"That's why we're really calling on them to have that clarity of purpose, have those discussions, step away from the work for a bit and say, 'what are we trying to achieve here? What does transformation actually mean?'
"That is what they're supposed to be doing. The joint venture is about transforming the way government works. You're not going to get transformation if you don't have those fundamental discussions.
"We note in the report has been a bit of action since we shared our findings with the joint venture, but we'll be looking keenly to see what progress they make from here."
Towers said he did not look explicitly at what the government was spending on dealing with family and sexual violence, but the report does not in 2015 it was $1.4 billion per annum.
"There have been major announcements of funding since that time, so it's really clear to everybody involved that not only is family violence and sexual violence, not only are they a huge problem generations in the making, but they also eat up a lot of resource across government.
"The fact there hadn't really been much of an improvement in the rates of violence was really a bit of a motivation for having the joint venture, so I think everybody realises that in terms of value for money or what we're getting from that huge use of resource - from frontline police through to policy work in Wellington - it hadn't been delivering."
The Auditor General's report urges ministers involved in the joint venture to get clarity on what they are trying to achieve.
Measuring success will come down to the group's strategy, Towers said.
"Without a strategy it's hard to know what you're trying to achieve. In the report we call out the fact that there hasn't been a strategy."
So far the group does not know what success would look like, he said.
"The joint venture shouldn't be seen as a programme of work or a project. It's a new way of working, a new way for government to work, it's the way they're going to work on family and sexual violence from this point on.
"So they don't have that clarity of vision yet, but we're really looking for them to deliver that in the not too distant future.
"They've had almost three years now. It was launched in September 2018. They're not as far along as they would like, or as we would have expected them to be at this point.
"I think it'll be a work in progress for a long time, it'll be something they have to continue to work on. Things like partnership with Māori, partnering with the NGO sector, partnering with communities. That's going to have to be something you consistently work on and over time.
"We generally have a process of checking in, after 12 months. But also this report is the start of a programme of work or the first product of a programme of work we've got underway on family violence and sexual violence.
"At the moment we are shaping up another performance, looking at the way those government agencies involved in the joint venture are working closely with the non-government sector via service providers, to see if they're doing that effectively, so service providers can deliver services New Zealanders need in the way they need them."
In a statement, Joint Venture deputy chair Andrew Kibblewhite said: "The Auditor General has acknowledged that while the Joint Venture has been a challenge for all those involved, it is the ‘right challenge’.
"The Joint Venture is about learning new ways of working that are different from how government organisations have traditionally worked. It is about working across all the agencies involved to achieve a common goal of eliminating family violence and sexual violence.
"This approach has developed and evolved over time. The Joint Venture has already made changes to address some of the issues raised by the Auditor General.
"All joint venture agencies are committed to bringing the work they do on family violence and sexual violence and connecting their efforts with their joint venture, community and Māori partners to make a real impact on this most challenging of issues.
"The new approach can be seen in the community led engagement on the national strategy to eliminate family violence and sexual violence that is currently underway."
