A clinical psychologist who met with more than 70 abuse survivors of the Catholic-run Marylands School in Christchurch in the early 2000s believes the St John of God Order was in complete denial that there was even a problem.
Dr Michelle Mulvihill, an Australian, who is a former nun, has given evidence to the Abuse in Care inquiry sitting in Auckland.
She describes St John of God as masters of cover-up and moral simpletons.
Mulvihill first worked with the St John of God Order in Australia after allegations of abuse first surfaced. After that she became in involved with claims from former Maryland School survivors.
She said it was impossible to believe the abuse was not witnessed by the religious Brothers in the Order who did not have allegations made against them.
Mulvihill said it soon became clear the Order was in a state of denial, and still is.
"The problem of denial was the collusion between those members of the group who had large numbers of members who had accusations against them. Protecting those who had been finally found out and either arrested or extradited."
Mulvihill said the survivors she met with were hurt, frightened and desperate.
She said it was impossible to believe the abuse was not witnessed by the religious Brothers who did not have allegations made against them.
She said the problems faced by the Order were extensive and she wrote to the Prior-General, the world leader of St John of God, based in Rome, expressing grave concerns.
"There is a culture of collusion inside the province (St John of God, Oceania) which is deeply ingrained, which makes it almost impossible for the truth about these matters to be dealt with."
Mulvihill said after the order gave survivors some financial aid, it suddenly decided to wipe its hands of them, which she describes as secondary abuse.
After nearly 10-years working to help the Order, she resigned, which coincided with the election of a new Provincial leader for Australia and New Zealand.
She said of the three candidates short listed, two had abuse allegations made against them.
The one who did not, Brother Timothy Graham, got the job and she met with him.
"What I found was really a snap-frozen disinterest in victims."
She was shocked with what Brother Timothy said to her.
"'Oh, Michelle, we are so vulnerable. There are so many people out there who are after us for our money.' I was gob-smacked. We are so vulnerable? What about victims are so vulnerable.''
Mulvihill said she had become a nuisance to St John of God and they could not wait to see the back of her.
She said there was just a complete lack of empathy for anybody.
"These people are the masters of cover up and in my view, moral simpletons. For decades they have fashioned the capacity to hide from the challenges of the real world and the psychological toll accrued on victims is totally unforgivable, if irreparable.
"When an organisation becomes so corrupt and I don't mean financially corrupt, I mean corrupted that they lose their way, they no longer see the effects of their behaviour originally on other people."
Mulvihill said St John of God did not fulfil its mission in New Zealand and were in fact doing the opposite.