Hackers have posted the email addresses and encrypted passwords of thousands of British defence, intelligence, police officials and politicians on the internet.
In an embarrassing breach of security at the heart of government, Cabinet Office personnel as well as advisers to the Joint Intelligence Organisation – responsible for assessing intelligence from sources including MI6 secret agents and passing information on to the Prime Minister – were also exposed, along with Nato advisers.
The breach came after self-styled "hacktivists", thought to be part of the Anonymous group, gained access to the account information of Stratfor.
A consultancy based in Texas, Stratfor offers analysis of international affairs, including security issues, and counts government departments responsible for sensitive information among its users.
The posted information exposed the user IDs – mostly email addresses – and encrypted passwords of about 850,000 individuals who had subscribed to Stratfor's website, The Guardian said.
British officials, speaking on condition of anonymity, said the leak did not pose a risk to national security, but it is believed intelligence agencies are still unsure about its full significance.
Analysis from John Bumgarner, an expert in cyber security at US Cyber Consequences Unit, a research body in Washington, revealed among the leaked email addresses were 221 Ministry of Defence officials – including army and air force personnel – and 242 Nato staff.
Seven Cabinet Office officials have had their details exposed, 45 Foreign Office officials, 14 from the Home Office, 67 from Scotland Yard and other police officials, and two royal household employees.
Stratfor removed its website from the internet while it investigates the breach. The company said it was "working diligently to prevent it from ever happening again".