Newshub can reveal the Education Minister's office instructed officials to delay the release of attendance data so it could be timed with a truancy announcement.
Jan Tinetti has previously said she had nothing to do with the delay and now the National Party is accusing the minister of being caught in a lie.
The minister was at Naenae College talking periods on Thursday.
"It just happened to me at school as well. I was mortified, I thought I was dying," she said.
Normalising menstruation here has even helped attendance.
"They didn't have enough money in their households for products so they couldn't come to school," she said.
The minister's under pressure to get more kids to school - only half attend regularly.
Tinetti is also under pressure about the attendance data itself and whether her office instructed officials over when it should be released.
In February, under fire in the House, she said: "I can categorically tell that Member that the Ministry of Education is responsible for the data. I have no say over that."
Newshub can reveal the minister's office very much did have a say over that.
Emails obtained under the Official Information Act show that on December 14 the attendance data was ready but the minister delayed the release saying she wanted more information.
On February 14, Tinetti's office told officials the plan is to release the data after her upcoming truancy announcement
A week later the ministry again asks when it will be released and her office again replied it would be after the announcement.
"This stinks to high heaven. The Minister of Education should have known that her staff were actively planning behind the scenes," said National's education spokesperson Erica Stanford.
Newshub asked Tinetti if she was aware her office was holding up that data release.
"Not at that time," she said.
Stanford said: "She's got caught out in a lie and tried to cover it up."
But Tinetti said there is "no lie there".
"Absolutely no lie there. I stand by my statement at the time in the context that I made it."
The minister was forced to correct the record in the House, only after the emails were released.
Whether she knew or not, ministers and their offices shouldn't be meddling with ministries' public information to try and time it for their own political announcements.
