Shortfalls around professional behaviour and use of force documentation, along with the "unacceptable" use of CCTV cameras in some cells were also flagged by Chief Ombudsman Judge Peter Boshier following the October 2020 inspection.
Corrections chief custodial officer Neil Beales said better training around mental health was needed and corrections officers had to uphold standards, but the concerns about dignity and privacy had no easy fix.
The report was published yesterday, following delays caused by the Covid-19 pandemic.
It found CCTV cameras were "a significant privacy issue" in three areas of the prison - management units, the receiving office and the intervention support unit (ISU) - where prisoners at risk of self-harm are kept.
In a 2016 inspection of the prison, the ombudsman had recommended that cameras should not cover toilets, which was reiterated in a 2019 follow-up report.
Because the prison did not have a youth unit, inmates under the age of 18 were placed in the ISU while they waited transfer to another unit and were exposed to CCTV surveillance, even if they were not assessed as at risk.
In the ISU, staff told inspectors they had little mental health training and learnt most of their skills on the job.
While training was meant to be provided, investigators found no evidence ISU staff were receiving any specialised mental health training.
Of the 35 use-of-force incidents reported by prison staff in the year to September 2020, six (17%) of them happened in the ISU, which has eight cells.
The majority (65%) happened in the prison’s three high security units where 225 beds were located, out of a total of 454 beds at the site.
Heavy use of pepper spray was raised as a concern, it being deployed in 10 incidents.
Issues were raised with inadequate documentation in use-of-force incidents, with records not completed in a timely fashion and with signatures and dates often missing.
A review of camera footage in relation to the incidents found "inconsistent use of de-escalation techniques and that some staff used unprofessional language".
Three incidents showed an apparent unreasonable use of force, one of which was being investigated as unlawful by Corrections.
Some staff were seen referring to prisoners using derogatory terms and a relatively low level of ethnic diversity among staff was flagged.
The prison was praised for working to improve its relationship with mana whenua, after its relationship with Ngai Tahu declined since the prison was opened in 2007, the report said.
Mr Beales said Corrections was working hard to resolve the issue with CCTV by early 2023, but the issue was complicated because Corrections had a duty of care and a legislative change would have to happen.
"We’ve got to make sure that we don’t do something that actually gives us unintended consequences and end up with somebody getting seriously hurt," Mr Beales said.
He did not share the ombudsman’s concerns around pepper spray to the same degree, as rates of usage were relatively low at the prison and it was often safer than physical interventions.
While some training had been done around mental health, more needed to happen and the ombudsman was correct to call shortfalls out.
Prisons were not hospitals and Corrections staff were not medical professionals but staff were seeing more people with significant mental health issues.
It was likely that plans, referenced in the report, to introduce a new plan in July 2021 had been delayed by Covid-19, he said.
Mr Beales believed prison director Dave Miller would be disappointed in the findings around documentation but pleased it had been picked up.
Accurate and timely documentation was hugely important to Corrections and it could not be allowed to ebb away around the edges when issues such as staff shortages affected operations.
There was no doubt the issue had been worked on already and a difference had already been made, Mr Beales said.
Any incident involving inappropriate use of force or language was not acceptable and staff were expected to remain professional at all times regardless of what they were facing, Mr Beales said.
His request to staff was to heed issues and improve safety through gaining trust.
