Acting Education Secretary Peter Hughes says human error is to blame for the exam results of 38 students being emailed to the wrong recipients.
More than 5000 students voluntarily took part in a PISA international study, which assesses and compares how well countries are preparing their 15-year-old students.
About 2500 students wanted their results emailed and 38 were sent to incorrect addresses.
Mr Hughes said some of the addresses handwritten by students were read incorrectly.
The students will be contacted and the wrongful recipients of the emails have agreed to destroy the information.