A 35-year-old Dutch citizen has been arrested in northeastern Spain in connection with the biggest cyber attack in history, police said Sunday.
Sven Olaf Kamphuis was allegedly behind a distributed denial of service, or DDoS, attack that took down the Internet last month.
Kamphuis was arrested Thursday at the request of Dutch judicial officials under a European warrant.
Investigators searched the suspect's residence, police said.
The investigation started in the Netherlands last month after a series of attacks were staged on an anti-spam company.
The attacks also affected the United States and Britain, officials said.
Investigators identified Kamphuis, who lived in the Spanish city of Granollers, as the organizer of the attacks.
The suspect had turned his house into a "computer bunker" equipped with communications gear that he used to give interviews to media outlets following the cyberattacks.
Kamphuis told officers he was a diplomat and "minister of telecommunications and foreign affairs for the Republic of Cyberbunker," Spanish police said in a statement.
Police cyber crime units from the Netherlands, Germany, Britain and the United States provided support in the investigation of Kamphuis.