The Belgian government has ordered 17 Internet Service Providers (ISPs) to block access to four websites that publish details about convicted paedophiles.

The move was ordered because the government says it could lead to citizens taking the law into their own hands and attacking those named on the site.

Ironically, the 2001 law under which the action has been taken was introduced to combat the spread of child pornography on the net.

Dutch-based site and three related sites run by self-styled 'paedophile hunter' Chris Holksen has published the personal details of convicted Belgian paedophiles.

Under the law, the Public Prosecutor's office has the power to block information on the Internet if it constitutes a crime, if it is the result of a crime, or if it constitutes a 'breach of public order and public morals'.

Patrick Van Eecke, a professor of Information Technology Law at the University of Antwerp, says that publishing the personal details of the convicted paedophiles constitutes a danger to public order, as identifying the paedophiles could lead to vigilante-style attacks.

Some Belgian bloggers have accused the state of censoring the Internet.

Leading Belgian ISP Telenet says it is the first time the state has ordered the blocking of a site.