Education officials warned the Government that if it published full national standards data it would risk providing opponents with justification for criticising it.
Education Minister Hekia Parata released information on Friday showing how nearly 2000 schools in the country teaching five to 13-year-olds rated against the benchmarks in reading, writing and maths last year.
It prompted protests from education groups who did not want the results used to compare schools.
Since the release of the data, it has been revealed that schools were inconsistent in the way they measured student achievement, with some also failing to file the information correctly.
In a report sent to Ms Parata in June this year, the ministry warned against the wholesale release of the information
It said she should instead release it as part of a detailed report, outlining the problems with the data and how the issues would be addressed in the future.
The officials said if Ms Parata released the information alone, she would risk losing buy-in from teachers and education groups and provide justification for opponents of national standards.
