He is being held on computer misuse and fraud charges, and the police are currently going through material obtained from “a residential address.”
It is not clear from the Scotland Yard release with which hacking group the man is affiliated, but Sky News reported that he is “suspected of being a mastermind behind notorious international computer hacking group LulzSec.”
The release says the Metropolitan Police worked with the FBI and the local Essex Police on the arrest.
The FBI declined to comment on the arrest.
The news comes as a document posted on the site PasteBin suggests that LulzSec may have obtained the records of the entire British census, The Next Web reported.
The group has not yet officially confirmed the hack on its Twitter feed — which has acted as its most official channel of communication — but a release on the open site is in the style of the hacker group.
The group did tweet out a message indicating that it has reaped a lot of results from its newly launched AntiSec movement, which could include the census information.
Our next step is to categorize and format leaked items we acquire and release them in #AntiSec “payloads” on our website and The Pirate Bay.
The group also said that Anonymous and “rogue hacking groups” were making headway with the AntiSec movement, which specifically targets governments and high-profile institutions.
On Monday, LulzSec targeted the Serious Organised Crimes Agency, in some ways the British equivalent of the FBI, and claimed to have taken its Web site down. SOCA said that it took its site offline to limit the impact of an attack, the BBC reported.