The Justice Action Group is calling for an independent investigation of the Ministry of Health's role in the abuse of intellectually disabled residents at a residential home.
Documents obtained under the Official Information Act this week showed residents at Parklands, a facility on a farm south of Auckland, were poorly fed and abused by untrained employees.
JAG says it first complained to the ministry in 2001. Spokesperson Colin Burgering said the ministry is the main offender because it knew the abuse was happening for more than 11 years and did nothing.
He said an investigation is needed into the culture at the ministry that allowed the abuse to happen for so long.
The ministry says it is taking a more active approach in managing the poor performance of disability providers.
Spokesperson Jill Lane said an independent assessment commissioned this year will test how well it is supporting the safety and well-being of disabled people.