Taieri College in Mosgiel says it is doing everything it can to ensure students who sat the wrong papers in an NCEA maths exam earlier this week are not disadvantaged by the mistake.
About 70 students were entered in the wrong Level 1 Algebra and Graphing papers.
Principal Christina Herrick says the students ended up taking papers that were designed for candidates using special algebraic calculators.
She says the problem arose because of the similarities in the content of the papers and numbers which the school did not check as carefully as it should have.
Ms Herrick says the papers will be marked but students will have the opportunity to re-sit the standards again if they feel they have been disadvantaged.
The New Zealand Qualifications Authority says it is aware that the students sat the wrong papers.
It says there will be sufficient evidence to measure students against the standard they should have sat and they will be given the appropriate credit, including merit or excellence.
The NZQA says the National Certificate of Educational Achievement is part of the National Qualifications Framework in New Zealand, along with approximately 1,000 other qualifications.