The website of the Serious Organised Crime Agency (SOCA) was taken offline by a Distributed Denial-of-Service (DDoS) attack last night.
Although no claim of responsibility has been made, SOCA said that the attack did not ‘pose a security risk to the organisation'.
“We took action to limit the impact on other clients hosted by the [same] service provider," it said in a statement to the BBC.
“DDoS attacks are a temporary inconvenience to website visitors but do not pose a security risk. Soca's web site contains only publicly available information and does not provide access to operational material.”
While no responsibility was claimed, a tweet by the main Anonymous account made note of the attack.
"Tango down: DDoS attack takes down site of UK Serious Organised Crime Agency (Soca)” with a link to the BBC News story.
Pro-US hacker The Jester said in a tweet that the attack was likely a "retaliation to carder site takedowns last week".
Last week SOCA and the FBI shut down 36 websites that were believed to be selling stolen credit card information, with 2.5 million items of compromised data recovered.
Rob Rachwald, director of security strategy at Imperva called the takedown ‘significant' and said that taking the sites offline ‘was a serious blow'.
Nathan Pearce, EMEA product manager at F5 Networks, said the "bold move" was equivalent to "putting graffiti on the Scotland Yard sign outside their offices".
Soca was previously hit by a DDoS in June last year by the hacktivist group LulzSec. Jake Davis and Ryan Cleary were both arrested in connection with the attack.
Ovum senior security analyst Andrew Kellett said security should have improved to counter DDoS attacks.
“Comments suggesting that ‘DDoS attacks are a temporary inconvenience' do not always fit the reality. Hacktivist attacks targeting particular operations have been known to be both persistent and longstanding, requiring extensive DDoS defences."
“Under the circumstances the actions of the agency appear to have been prompt and correct. They look to have spotted the attack quickly and by taking their site down reduced the impact on others who share the same service provider resources.”