WELLINGTON, Jan. 7 -- Hackers claiming to have accessed more than 100,000 people's health records in New Zealand have reportedly extended a ransom deadline until Friday, after saying they want to build a "good reputation".

The privately owned Manage My Health platform said cybercriminals had accessed the records of six-to-seven per cent of its 1.8 million users in the country.

New Zealand authorities have not named the suspects behind the data breach, discovered by Manage My Health on December 30 when it was tipped off by a "partner".

But a Telegram user named "Kazu" has claimed to have broken into more than 428,000 files on the Manage My Health platform, offering samples for download.

"Kazu" said it had demanded a ransom of US$60,000...