The site, sexbrott.com (previously known as sexoffender.nu), publishes names, personal identity numbers, addresses, convictions details and sentences.
There is a also a search engine with maps showing where the sex offenders currently live.
“We consider the publication to be a serious breach of privacy laws. That is why we are now reporting the site to the police,” said Data Inspection Board head Göran Gräslund in a statement on Tuesday.
The site was founded by a group of concerned parents in the autumn of 2008.
“We think that you have the right to know if a known sex offender lives in your neighbourhood. No one wants their children to be near a convicted paedophile,” one of the site’s founders said to Nyheter 24 when the investigation became known.
“The state should protect law-abiding citizens.”
Gräslund explained that these types of personal integrity infringements are a common occurrence on the internet. The board has been examining several similar websites in recent months.
The Local reported in January that organized crime network The Original Gangsters had taken over a similar website kriminellt.com as the site’s founders, another group of concerned parents, had been subjected to threats.
Since the launch of the board’s investigation and the resultant media exposure, sexbrott.com has not been available for viewing.
It is unclear if the site has been closed or is experiencing technical problems.
Gräslund confirmed that the site’s apparent closure does not affect the authority’s decision, however.