The top researcher for the Department of Corrections has linked patriarchal societies - Maori in particular - with a pre-disposition towards raping women.
Maori culture was flagged in a review by Corrections' senior research adviser, Dr Nick Wilson, regarding the pilot of a programme developed to treat high-risk rape offenders.
In his review, Dr Wilson found two-thirds of all "high-risk" rapists, and half of all inmates sentenced for rape, were Maori.
Those men were "significantly younger" than other rapists, the research showed, and tended to receive longer sentences.
Dr Wilson wrote that rape was "socially defined" and most likely to occur in cultures that were violent and where males were considered dominant. In a paragraph discussing violence, and "ideology of male toughness and war", he wrote:
"It is interesting to note that Maori have a proverb that states 'for women and land men die'."
Maori were the only New Zealand culture mentioned in that analysis.
When questioned about that line, Dr Wilson said: "That was a proverb from the past... I wasn't meaning it to say that necessarily Maori will still endorse that - but they have in the past. Whether Maori still endorse those beliefs, I'm not sure - but it has been in the past. And I certainly acknowledge that Maori are over-represented in terms of violent crime.
"It doesn't help that many of the more serious serial rapists have been of Maori descent."
Maori commentator Willie Jackson said the report was "a load of bloody nonsense. Having been one all my life, we find [rape] as offensive as anyone else... There's just as much abhorrence of rape as there are from Pakeha people, you know?"
Jackson said Maori did have different ways of dealing with rape and other crime, but that did not mean they were more accepting of it.
"Sometimes giving your people a second opportunity can be mistaken as accepting some of the crimes they've committed in the past - but don't confuse giving a person another opportunity as accepting what they've done."
There was nothing new in the statistics, Jackson said, but it was not a cultural problem - instead, he said, the numbers revealed more about the situation Maori were in.
"You put anybody into a certain condition... whether they're black, white, green or purple, and you look at the crime rate. You look at what happens."
Dr Wilson said there was a need to investigate the link between culture and rape, and he hoped that research could help in further treatment of offenders.
Europeans made up 30 per cent, Pacific Islanders 16 per cent and "others" 4 per cent of those sentenced for rape in New Zealand prisons, the report said.
But statistics could be skewed by women choosing not to report rape, particularly within marriage.
The programme, still in its fledgling stages, is the first to target high-risk rapists in New Zealand, despite international studies showing that rapists are more likely than child sex offenders to re-offend. The Ministry of Justice identified the treatment of rapists as a priority in June 2004.
New Zealand already runs two prison-based child sex offender programmes, and community-based programmes funded by Corrections and Child, Youth and Family, delivered by the SAFE and STOP networks.
These began in 1989.
Dr Wilson said child sex offenders had "always been well-catered for - they're easier to deal with... they don't have the violence...
"It's the squeaky wheel - well, rapists weren't squeaking as much as the other groups."By Catherine Woulfe Email Catherine