People's data has been stolen from MediaWorks and published online, the company says. Photo: RNZ / Marika Khabazi
More than 400,000 people have had their information taken in a cyber attack on MediaWorks.
The company said the attacker took information from a database of online competitions from as far back as 2016.
Initially it was thought as many as 2.5 million people could have been affected with alleged hackers demanding cryptocurrency in ransom.
Information shared included names, dates of birth, gender, addresses, email addresses and phone numbers - and in some cases, images or videos that may have been submitted as part of the entry.
Have you been caught up in the breach? Share you story with us at: iwitness@radionz.co.nz
The company had emailed those affected.
It said the attacker had published information online.
MediaWorks said it was reviewing its IT systems and cyber security protections.
Chief executive Wendy Palmer apologised for the concern and inconvenience caused by the breach.
"We want you to know that MediaWorks takes data security seriously and is working hard to make sure this doesn't happen again."
A woman whose personal data was among the data stolen says she's frightened about what the hackers might now be able to access.
Rebecca, who asked to keep her surname private, is worried the hackers might be able to get into her emails, social media accounts, or worse.
She says the email from MediaWorks was not very reassuring.
The Privacy Commissioner and police have been notified.