The police watchdog has found officers failed twice in their duty of care to a woman who was trying to harm herself.
In October 2017, the woman was left unattended in a holding cell, where she tried to self-harm.
The woman fell to the floor where she was unnoticed by staff for more than five minutes. When the woman was discovered on the floor, police put her in the recovery position but failed to notice her attempt to self-harm.
On a second check in, the woman's self-harm attempt was noticed and she was sedated and placed in intensive care where she was discharged two days later.
In November last year woman was arrested again and placed in a cell. Another prisoner was put in a cell with her and activated the call button 30 minutes later after she noticed the woman did not appear to be breathing.
Police took several minutes to respond to the call. It was discovered she had attempted to self-harm again and she was transported to hospital.
Independent Police Conduct Authority chair Judge Colin Doherty said there were a number of failings by police officers over communication and the accuracy of their risk evaluations.
The report found the woman was not monitored properly, and concerns about her behaviour were not passed on.
"It is evident that in both instances Police did not sufficiently fulfil their duty of care to her," Judge Doherty said.
Counties Manukau District Commander Superintendent Jill Rogers says police accept the report's findings.
"In these two instances we clearly did not provide the duty of care that is expected when monitoring people being held in our custody unit, particularly those individuals identified as being at-risk.
"This is obviously disappointing and we acknowledge that there were several shortcomings identified by the police staff involved in these two incidents.
"We have investigated this matter and identified learnings where we can improve our practices," he said.
Superintendent Rogers said since the incident they have notified the IPCA that the Police are in the process of implementing a plan to improve the way staff evaluate and monitor individuals held in custody in order to prevent this from happening again.
Where to get help:
Need to Talk? Free call or text 1737 any time to speak to a trained counsellor, for any reason.
Lifeline: 0800 543 354 or text HELP to 4357
Suicide Crisis Helpline: 0508 828 865 / 0508 TAUTOKO (24/7). This is a service for people who may be thinking about suicide, or those who are concerned about family or friends.
Depression Helpline: 0800 111 757 (24/7)
Samaritans: 0800 726 666 (24/7)
Youthline: 0800 376 633 (24/7) or free text 234 (8am-12am), or email firstname.lastname@example.org
What's Up: online chat (7pm-10pm) or 0800 WHATSUP / 0800 9428 787 children's helpline (1pm-10pm weekdays, 3pm-10pm weekends)
Kidsline (ages 5-18): 0800 543 754 (24/7)
Rural Support Trust Helpline: 0800 787 254
Healthline: 0800 611 116
Rainbow Youth: (09) 376 4155
If it is an emergency and you feel like you or someone else is at risk, call 111.