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 by 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. 

The company had emailed those affected. 

It said the attacker had published information online. 

The latest message from the MediaWorks hacker. 

Mediaworks said it was reviewing its IT systems and cyber security protections. 

Chief executive Wendy Palmer apologised for the concern and inconvenience caused. 

“We want you to know that MediaWorks takes data security seriously and is working hard to make sure this doesn’t happen again.” 

The Privacy Commissioner and police have been notified. 

-RNZ