A clinical psychologist has likened the treatment given to young people at Lake Alice Psychiatric Hospital in the 1970s to tactics used by those such as the Nazi's secret police, the Gestapo.
The Royal Commission into Abuse in Care has heard from survivors who were given electric shock treatment as punishment while in the child and adolescent unit.
They were also subjected to high doses of drugs and sexual abuse.
Expert witness Dr Barry Parsonson said the electric shock treatment, rather than it being aversion therapy - as claimed by the lead psychiatrist, Selwyn Leeks - it was a form of torture.
"The only people who did that were state organs of terror, namely the Gestapo is a good example. I have read of people who have received that sort of treatment [electric shocks to genitals] from the Gestapo."
What happened at Lake Alice never even met the basic criteria of aversion therapy, Dr Parsonson said.
''A the very least, the actions of Dr Leeks and the unit staff was an abuse of power and medical authority. An unjustified assault on the human dignity and rights of the young persons and an inhumane regime of maltreatment that induced fear, anxiety and terror," he said.
''As well as causing lasting emotional and physical harm to those forced to suffer the ordeal of Lake Alice Hospital at that time.''
There was nothing therapeutic about the so-called treatment carried out by Dr Leeks and his team, he said.
''But [it was used] as a means to punish a range of behaviours they deemed as undesirable through the intentional use of force to induce pain.
''From a clinical and ethical perspective, there are no scientific or medical or therapeutic justifications for the use of electric shock, paraldehyde [drug] or seclusion in the practices adopted and abused by Dr Leeks and the senior nursing staff of the unit in their treatment of children entrusted to their care.''
Dr Parsonson said there was no evidence in the documentation he reviewed that the procedures, to which these children and young persons were subjected, were in anyway consistent with either aversion therapy or operant punishment procedures available from the published literature of the time.
It was cruel and unusual punishment, he said.
''[It] applied in ways that fit the definition of torture.''
One issue for the Royal Commission to think about was where on the scale from maltreatment to torture did this unjustified exposure to institutional violence sit, he said.
Bryon Nichol spent six months in the Lake Alice unit at the age of 12.
He said he received electroconvulsive therapy (ECT) many times, which was always unmodified, and without a muscle relaxing anaesthetic.
"The nurses would come down and drag me upstairs. I was often so petrified that I soiled myself. They would put a mouthguard in my mouth and held me down while Dr Leeks gave me ECT. The ECT would give me vicious pains in my head and make me feel dizzy and as it continued the pain got worse. My arms and legs flailed about. It was absolute agony."
At one stage, Nichol tried to runaway and as a punishment Dr Leeks gave him electric shocks to his feet.
''In some ways, the pain was worse because it ran up into the rest of my body and I believe this is why I have trouble with pins and needles in my legs.''
He told the Royal Commission that his life has been totally screwed up following the treatment he got at Lake Alice.
''I am still haunted by the trauma of Lake Alice and particular the memories of being raped, and seeing a mentally disabled boy being injected into his penis, the smell of urine and faeces swelling up in our pants and dripping down our legs while waiting in fear for ECT, and begging for help while being sexually abused, and being called a liar and being punished for it.
''These are the worst memories and they flash up daily.''
RNZ