The New Zealand Qualifications Authority has accidentally let more than 200 students see their NCEA results.
The error occurred on Monday morning when the authority was testing its website in preparation for the publication of last year's exam results on its website later in the week.
The authority ran the test for just five minutes from 6.25 to 6.30am, but during that time there were 265 log-ins to the student results held on the website.
The incident sparked a flurry of queries from students wanting to know if the results they had seen were valid, and from others who wanted to know why they could not see their information.
The authority has told students that the results are preliminary and the official release date is later this week.
NZQA says it will tell students via Twitter and the media when the results are available. Until then, it has blocked the student log-in to its website.