The Ministry of Education removed information about the former iteration of charter schools from its website ahead of the announcement they would be re-introduced, over concerns it would be confusing and out-of-date.
While the ministry says it was part of regular website maintenance, the Green Party is questioning the timing, saying submitters on the legislation and prospective parents should have had access to the information.
The minister responsible for charter schools, meanwhile, thinks the Greens are playing gotcha politics.
In May, 15 pages and their associated documents were removed from the ministry's website.
They included information about the previous model of charter schools that existed, such as the development of the policy and its eventual repeal, as well as "close out reports", which contain detailed assessments of how the scheme went the first time around, including what went well and any shortcomings.
The Green Party's education spokesperson Lawrence Xu-Nan said such information would have been useful and was concerned at its removal.
"When people are making submissions, people would like to know the most amount of information, particularly the lessons learned from the last time we had charter schools," he said.
"For them to remove that, it means we don't have the transparency, or even some of the level of appropriate decision-making when we're looking at submitters being able to make their submission with full information."
Reintroducing charter schools is part of National's coalition agreement with ACT, with the work spearheaded by Associate Minister of Education David Seymour.
The pages were archived from the Ministry of Education's website on 8 May.
Seymour officially announced the funding for 50 charter schools on 14 May. The bill was introduced on 26 June and applications opened on 11 July.
There was no instruction from Seymour or his office to remove the material.
An email chain obtained by the Greens under the Official Information Act shows the ministry requesting the information be removed.
"In doing a bit of research to answer a query our office received, I stumbled across these pages," a principal advisor said on 7 May.
"You'll note that they're very much out of date in relation to work being done on charter schools. Please can I ask your team to take a look (soon) and take down any pages that contain out of date and now incorrect information?"
Following up, a principal business partner instructed the ministry's web team leader to take the pages down.
"The web team were going to take these down ages ago but the CS team wanted them kept up because they were using them. We offered them an alternative but I never heard back," they said.
The documents were removed the following day. The pages on the website still say "page not found".
A response to the Greens from the ministry's acting deputy secretary Rob Campbell said the information was removed as part of the ministry's usual maintenance process.
"The ministry regularly reviews our website content for relevance and correctness. Where pages and documents are found to be out-of-date or no longer fit for purpose, we will archive them," Campbell said.
Xu-Nan argued the information was not out-of-date, as members of the public may have wanted to refer to them when making a submission on the bill, or in deciding whether they wanted to send their child to a charter school.
"If they say it's part of maintenance, then they wouldn't have asked the team to remove it deliberately," he said.
"It seems contrary to appropriate decision-making, and giving the public the most information possible when it comes to making decisions or making a submission."
David Seymour said the Green Party was being desperate.
"The Greens could be focused on student achievement but instead they're attempting gotcha politics over some website maintenance."
Campbell told RNZ the documents were removed after a quality check of the charter school web pages to prevent any confusion arising from current and historical charter schools information.
"Our website is about nine years old (twice the average lifespan of websites) and we haven't had robust processes in place to make sure the information on the website is consistently reviewed for relevance and updated, replaced or removed when appropriate," he said in a statement.
"There are more than 16,000 files hosted on the site. This, combined with an outdated search function and lack of other user-friendly features has made it difficult for users to reliably find relevant and up to date information."
Campbell said for this reason, web pages that were of high current relevance were often reviewed.
He said work was underway to develop a specific page for proactively released advice and information related to the reintroduction of charter schools. A new website has been set up for information on their reintroduction.
Copies of the close-out reports are available on the ministry's website, on its section of OIA responses.