The Serious Organised Crime Agency website has temporarily been taken offline after a cyber attack by hackers.
The distributed denial of service (DDOS) attack, which involves websites being hit by a flood of users at the same time, was carried out on Wednesday night.
However a Soca spokesman said the incident did "not pose any security risk to the organisation".
DDOS attacks have previously been linked to the international hacking 'collective' Anonymous.
The Soca website was taken down at 10pm on Wednesday night. "The action was taken to limit the impact of a DDOS attack on other clients hosted by our service provider," said a spokesman.
He added that the attack did not pose a threat to any ongoing operations: "Soca's website contains only publicly available information and does not provide access to operational material.
"Soca does not consider it to be a proportionate response, or a responsible use of taxpayers' money, to maintain excessive bandwidth on the off-chance of a DDOS attack on a public-facing website."
On April 27, Soca shut down 36 websites that it believed were used to sell data from credit and debit cards.
LulzSec's alleged Soca attack
Soca website has sustained previous cyber attacks by hackers. Ryan Ackroyd, charged with involvement in the 'hactivist' group LulzSec's hacking of Soca and CIA websites, appeared at court in March and entered no plea.
During the hearing, Westminster Magistrates' Court heard that the 25-year-old allegedly attempted to access NHS and News International websites illegally.
He will appear at Southwark Crown Court on May 11 and is currently on bail until then, but under stringent conditions: he is not allowed access to the internet or to have possession of a smartphone.