Spanish police have arrested a Dutchman suspected of being behind one of the biggest ever web attacks.

The 35 year-old-man was detained in Barcelona following a request from the Dutch public prosecutor.

The attack bombarded the websites of anti-junk mail outfit Spamhaus with huge amounts of data in an attempt to knock them offline.

It also slowed data flows over closely linked networks and led to a massive police investigation.

The man arrested is believed to be Sven Kamphuis, the owner and manager of Dutch hosting firm Cyberbunker that has been implicated in the attack.

"Spamhaus is delighted at the news that an individual has been arrested and is grateful to the Dutch police for the resources they have made available and the way they have worked with us," said a Spamhaus spokesman.

He added: "Spamhaus remains concerned about the way network resources are being exploited as they were in this incident due to the failure of network providers to implement best practice in security."

Spamhaus servers were hit with a huge amount of data via an attack technique known as a Distributed Denial of Service (DDoS) attack. This attempts to overwhelm a web server by sending it many more requests for data than it can handle.

A typical DDoS attack employs about 50 gigabits of data every second (gbps). At its peak the attack on Spamhaus hit 300 gbps.

BBC News