Launched on Monday, Lexbase.se allows people in Sweden to look up a friend's, colleague's or neighbour's criminal record online.
Searches can also be carried out by neighbourhood, with red dots signalling the presence of convicted criminals on a map.
The site prompted Kristina Svahn Starrsjö, head of Sweden's Data Protection Board (Datainspektionen) to pen an op-ed in the Dagens Nyheter (DN) newspaper calling for changes to Sweden's constitution to stop "abuse" of loopholes to the detriment of individuals' privacy.
"As things stand now, there's nothing stopping a website from publishing sensitive information about convicted criminals for at least five years," she wrote.
Svahn Starrsjö explained that her agency's "hands are tied" when it comes to addressing Lexbase.se and other sites that publish personal information like criminal records because the sites' publishers have paid the 2,000 kronor ($312) fee to obtain a publishing licence (utgivningsbevis) from the Swedish Broadcasting Authority (Myndigheten för radio och tv).
"There's nothing we can do about the site, no matter how much we want to," she wrote.
A publishing licence gives web publishers the same constitutional protections offered to broadcasters, newspapers, and traditional media outlets.
"It's an undeniable paradox that anyone who has a website and a publishing licence can freely handle information in a way that police are prohibited from doing," Svahn Starrsjö explained.
The constitutional protections afforded publishers trump privacy protections enshrined in Sweden's Personal Data Act (Personuppgiftslagen, PUL), she added.
Svahn Starrsjö pointed out that her agency first warned the justice ministry about the problem back in 2009, resulting in changes in 2011 that tightened rules for credit reporting companies.
However, addressing the problem associated with sites like Lexbase requires changes to Sweden's constitution, a process that requires two separate decisions by the Riksdag, as well as an intervening election.
"Thus, a parliamentary inquiry needs to be launched as soon as possible," she wrote.
At the same time, an increasing number of Swedes are seeking information from the country's crime registry, with DN reporting the number of extractions having increased five-fold in the last decade.
In 2013, 222,940 crime registry extractions were executed, most often by individuals in connection with a job application. While Sweden requires those working with children and young people to undergo a criminal background check, more employers in sectors that have no such requirement nonetheless want to know whether applicants have a criminal past.
The spike in criminal record requests prompted the government to review how criminal records are used in the labour market. The inquiry's findings are set to be finished in April.