The Guardian has written half a million users of its jobs site suggesting they take action to protect themselves from identity fraud in the wake of a hacker attack.
The site, which according to The Guardian is run by outside company Madgex, was targeted over the weekend.
In a message to users Guardian News and Media said: 'The Guardian Jobs website has been targeted by a sophisticated and deliberate hack, which has breached the security of the data on the site. You have used the site to make one or more job applications and we believe your personal data, relating to those applications, may have been accessed.
'We are absolutely committed to the privacy of our users, and would like to assure you that we are treating this situation with the utmost seriousness. The matter has been reported to the police, who are now undertaking a full investigation through the police central e-crime unit at New Scotland Yard.
'We have no reason to believe that any financial or bank data was compromised in this incident. However the police advise that those whose personal data may have been stolen in this way should take a number of precautionary measures."
These measures are to contact your creditors, so they can monitor your accounts, contact a credit reference agency who can help take preventative measures and to subscribe to fraud prevention service Cifas at a cost of £12. This last option places a notice on your credit file warning that you may be a target of identity fraud.