The disability sector says more money is needed to help those with complex needs.

In a letter to the Minister of Health, the sector warns a tragedy is only a matter of time.

Disability Support Network CEO Dr Garth Bennie told Mike Hosking the problem is not new, it's just getting bigger.

"Particularly those with high and complex needs, they need highly personalised arrangements that keep them connected with people, families and communities, and the approach to funding this group by the Ministry is making this more difficult."

Bennie said the funding they get doesn't recognise the indirect cost of providing services.

"People with more high and complex needs, those funding gaps can run into the tens of thousands of dollars funding per individual."