A hacker group called TeaMp0isoN says it has "owned" Tony Blair by posting online the former prime minister's national insurance number and address book, along with the CV of Blair advisor Katie Kay.
The apparent leak was announced by professed TeaMp0isoN member TriCk, whose group has reportedly tried to hack rival group LulzSec, in a series of Twitter posts late on Friday. It takes the form of a Pastebin document and contains dozens of names, numbers and email addresses. The contacts range from a dentist and a garage to former lord chancellor Derry Irvine, 10 Downing Street and the Groucho Club.
TriCk said in a separate tweet that two members of his group are from the UK and one from the US.
Entitled "Tony Blair and His Sheep Get Owned", the Pastebin document states that the information was taken from a webmail server in December last year. "Phone numbers may have changed but all the information is 100% legit," TeaMp0isoN says.
The group is reportedly antagonistic towards LulzSec, which has been responsible for hacks and other attacks on the UK's Serious Organised Crime Agency (Soca), entertainment companies, the NHS, the US Senate and the CIA.
Essex teenager Ryan Cleary remains in police custody charged with involvement in the Soca attack and others, carried out under the name of the Anonymous hacker group.
Earlier this week TeaMp0isoN defaced the website of a man called Sven Swootleg, who they said was a LulzSec member but who denies being part of that group. A message was put up on the site, taunting LulzSec and questioning that group's hacker credentials and threatening to expose its membership.
Swootleg said in a subsequent statement that he is "not a member of Lulzsec (a statement I have made several times before in various places), no-one 'hacked the server' (this has been verified by the hosting company, as this website is on shared hosting) and this was definitely not an 'elite hack'". He said TeaMp0isoN had exploited a plug-in in his "outdated WordPress setup".
UPDATE (2.16pm): CNN has a quote from Blair's office, saying the information was not obtained from Blair nor from any of his office systems.
"This appears to be information from the personal email account of a former member of staff from a few years ago," a spokesman is quoted as saying. However, TriCk said in a subsequent tweet that Blair's office was "lying" about how the information was obtained.
"We got into the webmail server via a private exploit and we wiped the logs, so good luck," TriCk wrote.