Former Government minister Clare Curran has assured Prime Minister Jacinda Ardern she is archiving all emails she sent using her personal Gmail account.
Ms Curran resigned as a minister last week after being unable to answer questions about what official work she had carried out on her personal email.
She was earlier sacked from Cabinet for failing to properly record a meeting for the second time.
Prime Minister Jacinda Ardern said today work-related emails on Ms Curran's Gmail account would be saved as official records and be discoverable under the Official Information Act.
Ms Curran said she was working with the prime minister's office to archive the information.
"I've given the prime minister an assurance that I'm archiving all of my Gmails, and I'm working through all of that at the moment, and they will be publicly discoverable."
She told reporters that would include all emails that involved ministerial work.
National Party broadcasting spokesperson Melissa Lee said she was worried Ms Curran would selectively archive her emails.
"She is deciding what is relevant and what is not but she is no longer a minister so I am a little bit concerned that we may not actually get to the bottom of it.
"What I would like to actually see is her being very open, finally, and give up all the Gmails that she has actually done work on so that we can actually, finally, get to the bottom and know the truth."
Ms Lee said Ms Curran should give up her password and someone else should decide what was archived and what was not.