The trial of a prisoner accused of raping three of his cellmates has begun in the High Court in Auckland.
William Katipa has denied 14 charges including sexual violation and threatening to kill.
Opening the case for the Crown, prosecutor Ned Fletcher warned: "This is a case about rape in prison and so I have to warn you that the content of what I'm going to tell you about is very heavy indeed."
The prosecutor said the first rape happened over 10 years ago as Katipa served a sentence of preventive detention, a term comparable to life.
Mr Fletcher said it started with a fight in a cell after lock down but Katipa then raped the man while they were locked inside.
"The defendant had told him that what had happened would happen again the following night and he couldn't handle that thought. He tried writing a rescue note on an envelope to slip under the cell door but when he tried to get off his bunk to do that, the defendant woke and told him to get back in bed."
The man had to wait until they were let out in the yard the following day to alert a prison guard.
Mr Fletcher said the guard would tell the court he put the prisoner in a holding cell while he supervised yard time. When he went to the cell a short time later, he found the prisoner with his head between his knees.
Mr Fletcher said the man told the guard: "You've got to get me out of here, mister".
"He then started sobbing uncontrollably, like a baby, for a good 10 to 15 minutes."
The man spoke to a police officer and despite Katipa's DNA being found on the man's boxer shorts, the police investigation was closed.
It was reopened years later when two other complainants came forward.
One teenager double bunked with Katipa inside the Serco-run prison at Wiri. Katipa, then 49, played the guitar and taught te reo and kapa haka. When the teenager moved in, he said he was repeatedly raped every night for a week.
When he was finally able to change cells, he said Katipa threatened him with a knife.
Mr Fletcher said another prisoner - who was in his 20s at the time - spent just one night with Katipa and was also raped.
He waited until Katipa was out of his wing before telling police what had happened.
The man was also threatened and Mr Fletcher explained how that threat was received.
"A lot of people will bow down to people that are lifers because ... for the reason that they can literally kill you and it wont do anything to their lag. What's an extra 10 to 15 years when they're already doing life?"
Mr Fletcher told the jurors that if they believed the men, then there was only one verdict they could return.
"Irrespective of why these young men were in prison and what you think of them, it's your responsibility to return guilty verdicts, because otherwise, the pernicious notion that prison rape is an inevitable part of prison life behind bars will continue."
Defence lawyer Andrew Speed told the jurors the allegations were untrue.
"They are motivated by self-interest, delivered by complainants for whom dishonesty is a way of life."
The trial before Justice Downs continues.