Edwards advised the public to inform the Ministry of Health or police if they are sent personal information, either about themselves or others, and seek advice on whether to delete it.
He warned that the hackers were likely to publish and circulate the information further.
"The information that has been taken is likely to be sensitive personal information. This is likely to be causing a great deal of anxiety to the people affected.
"It is vital that people respect the personal information of others. Treat the information as you would expect others to treat yours if it were disclosed to you. If you receive personal information which is about other people, you should inform the Ministry of Health and NZ Police."
Several media agencies were contacted this week by a group claiming responsibility for the cyber attack, via an email with attached files containing patient and staff information. The Herald has provided the email to police.