The head of the Education Ministry is investigating a senior official seemingly trying to "subvert" the Official Information Act.

Leaked footage given to the New Zealand Herald shows senior Ministry of Education official Catherine Law telling staff not to put information shared with the minister's office in writing and reminding them it was "OIA-able" - referencing the Official Information Act.

Law is also the principal of Avonside Girls’ High School in Christchurch.

Speaking to media, Erica Stanford said she was confident her Secretary of Education had the situation "in hand".

"She's already talked to the Public Service Commission, she's already talked to the Ombudsman, and she's already looking into the matter and taking it very seriously, as I expect that she would do."

Stanford denied instructing officials to subvert the OIA process.

"We take our obligations extremely seriously, and as I said, this is a matter for the Secretary of Education and her staff.

"My political staff and I have not seen the documents that she was talking about."

Asked if there was a culture where officials were trying to hide information so they did not embarrass her, Stanford said she hoped "that's not the case".

"I've always made sure that the Secretary of Education understands that we are abiding by the Official Information Act, and I've made that clear again yesterday."

Labour leader and former education minister Chris Hipkins said circumventing transparency laws was "inexcusable".

"Ultimately, ministers sign off the curriculum so there's there's nothing that should be secret here.

"There should be a transparent process around that, and trying to circumvent that so that you can make edits to the curriculum without anybody knowing that's what you're doing seems bizarre, secretive, and just inexcusable." he said.

Hipkins said he had not experienced a culture of hiding information to avoid the OIA process.