Guilty of rape: Brandon James Roche, of Papanui, left, and Brooke Christie Rolleston, of Cashmere, both 20-year-old plasterers.

Two men have been jailed for more than a decade each for raping a 15-year-old girl while she was drunk at a party.

Brooke Christie Rolleston and Brandon James Roche, both 20-year-old plasterers, were sentenced for rape and sexual violation in the Christchurch District Court on Wednesday.

A jury found the pair guilty in May over an incident at a party where they simultaneously had sex with the drunk girl at a house near Christchurch in January 2016.

The courtroom was packed and security was tight for the session, with three Corrections staff, three court security officers, and four uniform police flanking the two defends and effectively surrounding the public gallery.

Judge Alistair Garland started by asking the crowd to "behave in a proper and dignified manner".

In a victim impact statement, read in court by Crown prosecutor Deirdre Elsmore, the girl said she could no longer attend school without feeling unsafe.

"I am slowly getting back into mainstream school, but I am now a year behind where all my friends are."

She still struggled to concentrate and had nightmares. "I will do well because I want a future career, but this has been a huge setback." There were times when she could not stop crying and could not get out of bed.

"At times, the feelings are overwhelming," she said.

Her mother slept with her afterwards and would have scratches on her in the morning from her daughter's nightmares. The girl had no memory of inflicting these injuries.

Giving evidence in the trial had been "terrifying", she said. "I have lost who I am."

The two defendants sat shaking their heads sometimes while Judge Garland recounted what happened on the night of the rape. He said the girl was very intoxicated – wobbly on her feet and struggling to talk.

Late in the night, they had carried her from her bedroom where she had gone to bed. She had to be supported to walk. The pair took her into an empty bedroom where the offending took place.

Afterwards, the men were pleased with themselves, engaging in laughter and banter in the house and in a truck on the way home.

The girl was left to fend for herself, the judge said. She was clearly in distress and vomited. The next day, she had no recollection of the sexual activity.

He said the jury rejected their explanation the girl was consenting. He approached sentencing on the basis they knew she was so intoxicated she was not able to give genuine and true consent.

He said both men had been assessed as being a low risk of reoffending, but because they told a probation officer they rejected the jury's verdict it was hard to see they had learned anything and it was hard to accept they were a low risk.

He referred to their self-entitled and arrogant attitudes in their comments on Facebook and to the police afterwards.

Alcohol use was a factor for both men. The judge had read references for the men and noted that people had been shocked by the jury's verdicts.

Judge Garland jailed Rolleston for 11 years and two months, and Roche for 10 years and nine months – reduced because of his clean record.

The public gallery remained quiet, except for tears at the end and messages of support called to the men as they were led out.

For Rolleston, defence counsel Craig Ruane urged the judge to accept that the jury had reached its verdicts on the basis of "a mistaken belief in consent".

It may have been sparked by an apparent falling out between the victim and her boyfriend. There was evidence she was flirting with one or both of the men during the evening. That did not make her responsible for what happened, but it "may have led them to think their advances might be welcomed".

Defence counsel for Roche, Trudi Aickin, said the incident took place in a heady mixture of alcohol, at large gathering of young people, many of them uninvited, where there was a lack of adult oversight.

The evidence of kissing, dirty dancing, grinding, and "getting with" Roche by the victim could have led the jury to conclude that he believed she was consenting, but his belief was not reasonable in the circumstances.

Many of the rapists' supporters turned up at the courthouse wearing black t-shirts reading, "False evidence appearing real". They removed them before the sentencing session.

Judge Garland told the crowd: "You are entitled to disagree with the submissions or with the decision of the court, but what you are not permitted to do is to express your views out loud in this court room. Any person behaving in a disruptive or disrespectful manner risks being taken into custody."