North Shore City Council says it is undertaking a review of its internal security after claims by a councillor that someone forwarded emails from his computer to a Sunday newspaper.
Councillor Ken McKay says the council has reported the theft of personal information from the council computer to police.
Mr McKay says he left his computer unattended, but still logged-on, in his name on Friday afternoon.
When he logged-on to it from another room later that day, he says he received an email from a Sunday paper journalist thanking him for an email which he did not send.
He says a string of emails, including confidential information, had been sent to the newspaper from his computer.
Mr McKay says he considers this to be identity theft.
He says only a limited number of people have access to the councillors' work room and the action was clearly malicious.