The hacking group LulzSec has denied claims that it has intercepted the results of the 2011 UK census.

A statement posted to Pastebin said: “We have blissfully obtained records of every single citizen who gave their records to the security-illiterate UK government for the 2011 census. We're keeping them under lock and key though so don't worry about your privacy (until we finish re-formatting them for release).

“Myself and the rest of my Lulz shipmates will then embark upon a trip to The Pirate Bay with our beautiful records for your viewing pleasure!”

While details are unconfirmed on who was responsible for this, thenextweb.com claimed that the information captured is likely to include income levels, employment information, statements on religion, as well as names and addresses.

Rik Ferguson, director of security research at Trend Micro, said: “No details are included in the statement regarding how the information was obtained, but the messages posted so far seem to indicate a leak rather than an intrusion or hack.

“This could undermine the confidence of the nation and possibly others to hand over sensitive information to a civil service that has already once demonstrated their inability to encrypt or safeguard it. Currently refusal to fill in a census is a criminal offence in the UK, will we be looking at mass criminality when the next census rolls around?”

Yesterday LulzSec said that it was declaring immediate and unremitting war on the ‘freedom-snatching moderators of 2011', calling its actions ‘Operation Anti-Security'. It also called for supporters to ‘open fire on any government or agency that crosses their path'.

It said: “We fully endorse the flaunting of the word ‘AntiSec' on any government website defacement or physical graffiti art. We encourage you to spread the word of AntiSec far and wide, for it will be remembered. To increase efforts, we are now teaming up with the Anonymous collective and all affiliated battleships.”

A statement by the Office of National Statistics, said: “We are aware of the suggestion that census data has been accessed. We are working with our security advisers and contractors to establish whether there is any substance to this. The 2011 Census places the highest priority on maintaining the security of personal data. At this stage we have no evidence to suggest that any such compromise has occurred."

Responding via Twitter, LulzSec seemed to be unsure about the truth of the incident too. It said: “Not sure we claimed to hack the UK census or where that rumour started, but we assume it's because people are stupider than you and I.”

This tweet was removed shortly after, and replaced with: “Just saw the pastebin of the UK census hack. That wasn't us, don't believe fake LulzSec releases unless we put out a tweet first.

“Anyone in the world can copy and paste The Lulz Boat ASCII art and general lighthearted theme. Smarten up, check the feed first.

“But hey, if someone out there hacked the UK government in the name of #Antisec, well done sirs!”