A small number of schools is increasingly dominating the elite scholarship exams.
Qualifications Authority statistics show the same eight schools have topped the exams for two years running, and last year their share of the awards rose from one in five to one in four.
The Post Primary Teachers' Association's principals' council says that shows a growing disparity between rich and poor schools. "The polarisation is often organised around a socio-economic basis," says council chair Alan Vester.
But Wellington College headmaster Roger Moses says while that might be a factor, scholarship results also differ between schools of similar size and background. He says those that focus hard on scholarship are doing well in it.
"There are many schools who are taking scholarship very seriously, who believe that academic rigour is something really to be prized, to be aspired after," Mr Moses says.
"I think that there may well be a decreasing number of schools that are prepared to put the time in. I know certainly at Wellington College we spend a lot of time and focus on that. I'm not sure that other schools do."
Mr Moses says many other schools are focused on government priorities, such as raising NCEA level 2 achievement.