The site, stoppa-pedofilerna.se ('Stop the paedophiles'), allows users to perform geographic searches and includes the names, contact information, personal identity numbers (personnummer), and court rulings of those convicted of child sex crimes and child pornography offences.
Offenders listed on the site can have their information removed by undergoing “chemical castration”.
The man behind the site claims he simply wants Sweden to toughen its laws against paedophiles.
“In very extreme cases, we advocate life in psychiatric care,” the man behind the site told the Aftonbladet newspaper.
Jonas Agnvall, an attorney with Sweden's Data Inspection Board (Datainspektionen), said the agency has received numerous complaints about the site since it was launched two weeks ago.
According to Sweden's data protection laws, it is “prohibited for anyone other than a public agency to handle personal information about violations of the law which include crimes”.
Violating the data protection laws can result in up to two years in prison.
Agnvall explained, however, that the agency has yet to conduct a thorough investigation of stoppa-pedofilerna.se.
The Data Inspection Board has previously reported three similar sites to police in recent years, but investigations into two of those sites have since been dropped.
The man behind the site claimed that children are “safer” in the United States because many communities there have publicly available sex offender registers.
Until recently, he was a known member of the neo-Nazi Swedish Resistance Movement (Svenska motståndsrörelsen) but has since joined the Förbundet nationell ungdom ('National youth association'), which has the goal of “taking back” Sweden.
According to Aftonbladet, he spent two months in prison in 2009 for vandalism and making illegal threats against immigrants.
Daniel Poohl, editor of Expo, a magazine which tracks the extreme right in Sweden, said that the Förbundet nationell ungdom is also a part of a network of extreme right-wing groups in the country.
He explained that groups on the extreme right have long advocated tougher laws for child sex offenders in Sweden.
“It's part of their tough stance on crime and punishment,” he told The Local.
According to Poohl, the groups hope their “get tough” views on paedophiles will help them win new supporters.
“Interestingly enough, it's one of the few areas where they are colour blind. They don't care if the offenders are white or dark skinned,” said Poohl.
“Usually, these groups only draw attention to crimes involving immigrants.”
Nevertheless, Poohl expressed doubts as to whether the strategy of trying to target paedophiles would yield results.
“At first people may not realize it's an extreme right-wing group handing out a flyer [tougher sex crime laws], but once they start questioning democracy, most people lose interest,” he said.