A Northland primary school has asked an independent reviewer to investigate tampering with its students' national standards results.
Parua Bay School, a high-decile school near Whangarei, says it was told of changes to results in reading, writing and maths stored on its computer system in 2013, but its subsequent investigation did not reveal who was responsible.
The school told parents last week that results of 17 students were inappropriately altered.
The Ministry of Education said on Monday the school's board has told it that it is unclear what happened and who is involved, and it has brought in an independent reviewer to investigate more fully.
The board said the data altered in its computer system has been corrected and the tampering was a one-off event that will not be repeated.
Primary school union the NZEI said it is almost inevitable that schools and teachers will tamper with children's results in the national standards and the Northland case should be ringing alarm bells for the Government.
The Ministry of Education said it shows that the national standards system is working.