The Chief Ombudsman has delivered a scathing address to MPs about the Department of Corrections

Peter Boshier has addressed the Justice Committee about several unannounced prison inspections, ahead of his retirement.

He says there is good practice at Tongariro Prison and a caring attitude at Matawhaiti Residence - but says the state of Auckland Prison is regrettable.

Boshier says the use of segregation in higher security units risks breaching prisoners rights to human contact, impedes rehabilitation and is impacting mental health.

He says a lot of the work his office does with agencies is productive - but getting change in the Department of Corrections is like pushing a barrel of concrete uphill.