It was at this arrest that Ms X's father informed police that she required mental health support.
The arresting officer noted at the time the offender was "talking to herself ... highly agitated, sweating profusely", the IPCA report says.
While being arrested, Ms X told officers that she wanted "to kill myself".
The offender was taken to Whanganui police station, where she was processed and given a rub-down search by a female officer.
During the rub-down search Ms X began to undress, telling the officer "if I am going to the cells, I am going naked".
The search was conducted by the female officer while the offender remained in a pair of underwear.
After consistently refusing to get dressed, two male officers, Officer C and Officer D, came to assist with the request for the offender to dress.
Officer C succeeded in getting the offender to dress, by which point processing continued.
The offender suggested she wanted to have sex with Officer C, and pointed at her crotch.
Ms X was then moved to a cell. Having been informed of the offender's earlier suicidal comments, officers made the decision to ask her to again remove her clothes so she could be placed in a gown, the report says.
Both officers stood outside the cell while the offender put on the gown.
When officers D and C returned, Ms X had not followed instructions. She put the gown on top of her clothing and lay down on the bed, covering herself with a blanket.
The report says that while the offender lay on her side, Officer D picked her up with the gown arms holes and manoeuvred her body so she was lying face down.
He removed her long-sleeve top through the arm and head hole of the gown. He then cut the straps off her one-piece underwear with a small, foldable cutter.
The gown remained on Ms X throughout the process. Officer C stood to the side to assist if necessary.
Officer D left the room and asked two female officers to remove her leggings and underwear from beneath the gown.
The gown was placed on the offender, who was then left in the cell. While in the cell, the offender proceeded to commit a number of indecent acts.
The offender was later charged with committing an indecent act with intent to insult, resulting from her behaviour directed towards Officer C while detained.
The charge was later withdrawn by police, after Officer D, who filed the charge, failed to adequately review the charge documents, resulting in inaccurate information being provided to the court after a miscommunication between officers.
Cutting underwear 'lacked judgment' - ICPA
In the authority's findings, it said that the decision to detain and search Ms X was justified, but while no policy was strictly broken, the removal and cutting of the offender's clothing should have been undertaken by a female officer.
"Although Officer D did not breach a specific policy when he removed Ms X's clothing, with the availability of Officers A and B, both female, he did not display sound judgment and his actions had a detrimental effect on Ms X," the authority said.
The authority also said Ms X should have been gowned immediately after the rub-down search, rather than redressed and then told to put the gown on.
The Independent Police Conduct Authority also recommended police policy governing searching people should be amended to ensure gowning may be carried out only by a person of the same gender identity as the detainee, unless in extreme or urgent situations.
On the withdrawn charge, the authority believed that Officer D made a genuine error by relying on the information provided to him and not reviewing the charging documents.
But the behaviour of Ms X did meet the threshold for the charge to have been made and should have been reported accurately.
Responding to the decision, Inspector Allan said: "When issues arise, it's important we review our actions and, if necessary, make changes to ensure our staff are best placed to provide the service New Zealanders expect and deserve."
Police did not respond to the recommendation that policies surrounding gowning be amended.
