Nearly 400 foreign students will be retested after a New Zealand Qualifications Authority (NZQA) investigation into assessment problems at the International Academy of New Zealand.
NZQA deputy chief executive of quality assurance Grant Klinkum said the Auckland tertiary institution's setting, marking and moderating of assignments was unsatisfactory.
"Our review of over 100 items of assessment suggested that they weren't meeting the standards that NZQA would expect, and as a consequence we will be reassessing 380 students from a Level 6 business programme."
Dr Klinkum said the reassessment was necessary to validate the credits that the International Academy of New Zealand had so far given the students.
He said some might require as many as 12 hours of testing depending on how far through the business diploma they were.
The investigation began after a regular audit found problems in 2014, but the authority also received protected disclosures about the institution.
The institution was now being sold to another private tertiary institution called EDENZ Colleges, and Dr Klinkum said, if it was not being sold, NZQA would be considering a range of options, including deregistration.
He said the authority had actively worked with the International Academy of New Zealand to ensure their students were able to transfer to a high-performing education provider.
It was very rare that the authority needed to do an in-depth investigation of an institution's assessment practices, Dr Klinkum said.
Most of the students at the International Academy of New Zealand were from India, with a significant number from the Philippines.