Police arrest 19-year-old hacker

Updated at 3:30pm: The Metropolitan Police have arrested a 19-year-old in connection with denial-of-service attacks.

The teenager, from Wickford, Essex, was arrested after a joint investigation by the Police Central e-Crime Unit (PCeU), Essex Police and the FBI.

He was arrested under the Computer Misuse Act as well as the Fraud Act, and is being questioned in central London.

"The arrest follows an investigation into network intrusions and Distributed Denial of Service (DDoS) attacks against a number of international businesses and intelligence agencies by what is believed to be the same hacking group," the Metropolitan Police said.

"Searches at a residential address in Wickford, Essex, following the arrest last night have led to the examination of a significant amount of material," the statement added. "These forensic examinations remain ongoing."

The arrest raises speculation that the accused hacker is part of either Anonymous or LulzSec, both of which have targeted the UK Government, knocking the Serious Organised Crime Agency's site offline earlier this week.

LulzSec Census hack?

An online post reportedly from LulzSec also claimed to have captured details of "every single citizen" who filled out the UK's 2011 Census.

"We have blissfully obtained records of every single citizen who gave their records to the security-illiterate UK Government for the 2011 census," reads an IRC post purporting to come from the hacker group.

"We're keeping them under lock and key though... so don't worry about your privacy (...until we finish re-formatting them for release)."

However, subsequent posts on the hacking group's Twitter account denied responsibility for any attack on Census data. "Just saw the pastebin of the UK census hack," read a post on the @LulzSec Twitter account. "That wasn't us - don't believe fake LulzSec releases unless we put out a tweet first."

The Office of National Statistics said it was investigating the reported attack. "We are aware of the suggestion that census data has been accessed," an ONS spokesperson said.

"We are working with our security advisers and contractors to establish whether there is any substance to this. The 2011 Census places the highest priority on maintaining the security of personal data. At this stage we have no evidence to suggest that any such compromise has occurred."