Personal details of thousands of motorists have been mistakenly released by Wellington City Council's parking contractor in a massive privacy breach.
Responding to an information request from a member of the public, Tenix Solutions created a spreadsheet with data from about 120,000 tickets issued during the past two financial years.
But the company also mistakenly included personal information about the vehicle owners including their names, addresses and registration numbers.
Council chief executive Kevin Lavery said the person who requested the information contacted the council on November 19 to tell them of the privacy breach.
He then returned the three disks containing the information he was sent and satisfied the council the information had not been copied or used.
Mr Lavery said assurances had been sought from Tenix that the breach would not happen again and a full review had been sought.
"I have been clear with our contractor that its performance in this event was woeful," he said.
"We should all have every confidence that our personal information is secure and that there are processes and systems in place to ensure this does not happen again.
"I would like to unreservedly apologise to those individuals whose personal information has been disclosed and, again, thank the requester for returning the information."
The privacy commissioner had been informed of the breach.
If people were concerned their information may have been included on the disks they can email the council at email@example.com.