It was in August that the learning platform Vklass was hacked and personal data from 47,000 students from the city of Gothenburg was leaked.
The information was put up for sale on a website and was only discovered after two months.
The information concerns the students' names, school, schedule and grade.
Two people are now suspected of the data breach.
It remains to be seen whether the criminal classification will be gross data breach or breach of the normal degree.
- We don't have the whole picture ready, says Stefan Lind, preliminary investigation leader to the newspaper.
Inspected for leaks
According to the company, Vklass is Sweden's most used learning platform.
In the past, information has also been leaked from other municipalities and schools.
The incidents are now to be investigated by the Swedish Privacy Protection Authority (IMY).
- It is very sad and very serious that information has been leaked.
We have done everything in our power and informed all our customers, even those who were not affected, Andreas Selling, CEO of Vklass, previously told TT.
The information leaked from Gothenburg was put up for sale in an advertisement on the internet.
A serious problem, says cyber security expert Andrei Sabelfeld, who saw the ad.
Hear him talk more about the leaked information in the clip.
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"I don't have the database, but I have the ad" - start the clip to see the cyber security expert talk about the ad that allegedly sells the student data leaked from Vklass in Gothenburg.
Photo: Amanda Gustafsson/SVT