The website of Britain's Serious Organised Crime Agency (SOCA) has been taken offline after an attack by hackers, the agency said on Thursday.
It is the second time in a year that the website has fallen victim to hackers.
"We elected to take the website offline temporarily at about 10:00 pm (2100 GMT) last night," a SOCA spokesman said.
"That was as a result of a distributed denial of service attack on other clients hosted by our service provider. We would emphasise that our website only contains publicly available information."
The spokesman said the website would be back up "in due course".
The website was taken down in June last year after it was hit during a month-long rampage against sites which also included the CIA by the hacker group known as Lulz Security or LulzSec.
SOCA is a national police unit responsible for investigating organised crime.
Explore further: Huge YouTube bulk makes it tough to catch all terror videos