A member of the hacking group ‘TeaMp0isoN' was arrested in Britain last week and is being questioned on suspicion of offences under the Computer Misuse Act.
According to media reports, the 17-year-old male is known online by the nickname ‘MLT' and acted as a spokesman for the group.
The Telegraph reported that he was taken to a local police station for interview, and computer equipment had been seized and was undergoing a detailed forensic examination.
It was also reported that a 17-year-old and a 16-year-old were arrested last month and alleged to be members of TeaMp0isoN.
In that instance the group conducted an attack against Scotland Yard's counter-terror hotline, bombarding the switchboard with hundreds of calls by automating Skype software, and recording a conversation in which a counter-terrorism officer discussed the attack.
TeaMp0isoN targeted the United Nations in November 2011 and defaced the official BlackBerry blog after its parent, RIM, said it would co-operate fully with the Home Office and police following the London riots.
In January of this year, TeaMp0isoN published the names and passwords of T-Mobile staff after accusing the company of supporting the Patriot Act in the US.
A man from Shropshire was charged with hacking into the United Nations' computer systems in April.
Two Norwegian teenagers were also arrested on Wednesday in connection with the attack on the Serious Organised Crime Agency (Soca) website.
Norwegian prosecutor Erik Moestue told BBC News that he believed the 18- and 19-year-old men had also attacked the websites of the Norwegian Lottery and Germany's Bild newspaper, as well as American sites.