The 19-year-old man was apprehended by officers from the Metropolitan Police Central e-Crime Unit (PCeU) today in Wickford, Essex. The authorities have not named him, but local reports suggest that he is called Ryan Cleary.
Yesterday, the UK's Serious Organised Crime Agency (Soca), which is tasked with combating cyber crime, was forced to take its website offline after it was attacked by hackers from the Lulz Security (LulzSec) group.
Scotland Yard said that the arrest followed an investigation into "network intrusions and Distributed Denial of Service (DDoS) attacks against a number of international business and intelligence agencies by what is believed to be the same hacking group". However, it would not confirm whether the man was connected to LulzSec.
After the "pre-planned, intelligence-led" raid, the teenager was arrested under the Computer Misuse Act and Fraud Act and taken to a central London police station.
A Scotland Yard spokesman added: "Searches at a residential address in Wickford, Essex, following the arrest last night have led to the examination of a significant amount of material. These forensic examinations remain ongoing."
The LulzSec group has claimed responsibility for a number of website hacks in May and June, including The X Factor USA's contestant database, video games publisher Bethesda Softworks, SonyPictures.com and Nintendo.com.
A report was posted on the Pastebin website this morning claiming that LulzSec was behind a hack of the database of the 2011 Census, which carries details on every UK citizen who completed a survey earlier this year.
However, the group has denied the claim, posting on Twitter: "Just saw the Pastebin of the UK census hack. That wasn't us - don't believe fake LulzSec released unless we put out a tweet first."
Reacting to today's arrest, LulzSec added: "Seems the glorious leader of LulzSec got arrested, it's all over now...wait...we're all still here! Which poor b**tard did they take down?"