Law enforcement officials in Spain have arrested a Dutch man they believe is linked to cyber attacks that took place last month. The man was arrested at his home in Barcelona at the request of Dutch authorities. Police seized his mobile phones and computers during the arrest, according to reports.

The man, identified only as “S.K.” in a statement on a Dutch government website, was pegged as 35-year-old Sven Olaf Kamphuis according to unnamed sources as reported by the New York Times.

Kamphuis, the self-proclaimed minister of telecommunications and foreign affairs for the Republic of CyberBunker, is the spokesperson for a group that had previously protested tactics used by a European anti-spam group. He operates an ISP known as CB3ROB as well as web hosting company CyberBunker. Others, however, simply know Kamphuis as the Prince of Spam.

The incident took place last month when an anti-spam group called Spamhaus added CyberBunker to their blacklist. Many anti-spam groups (Spamhaus included) believe CyberBunker acts as a conduit for massive amounts of spam. Shortly after, Spamhaus fell victim to one of the largest DDoS attacks in history. The attack had far-reaching implications as the Internet slowed to a crawl for millions of people all around the world.

CyberBunker, a well-known hosting company that’s housed in an old five-story NATO bunker, famously offers hosting services to virtually anyone with the exception of those hosting child porn or anything related to terrorism.

An anonymous message posted to Pastebin proclaimed Kamphuis’ innocence and threatened another wave of attacks unless he is released.