The Department of Conservation (DOC) withheld official information after demands from security firm Thompson and Clark, internal emails show.
Thompson and Clark spied on anti-1080 activists for DOC, sharing intelligence through what it called its "Fusion Centre" - locked, hidden chat channels on messaging app Slack.
The work cost nearly $4000 a month - several government departments are signed up to similar packages - and also included a weekly phone briefing involving senior staff from both organisations.
But DOC withheld all material from the Slack channels when asked for correspondence between its staff and Thompson and Clark under the Official Information Act (OIA), saying releasing it "may prevent the supply of such information in the future".
The Ombudsman is investigating DOC's blanket withholding, but newly released internal emails between senior DOC staff and Thompson and Clark director Gavin Clark showed DOC was intending to release the material.
"Some, if not all, of the material in the Slack channel may need to be released under the OIA," DOC director of safety Harry Maher said in a 20 March email to DOC chief information officer Mike Edginton.
DOC and Mr Clark said the intelligence shared through Slack was all publicly available, drawn from the Internet.
However, on 28 March Mr Clark emailed Mr Maher with a warning.
"Thompson and Clark is unlikely to want to continue to provide DOC with such information if we don't have the confidence they can withhold it."
In that email Mr Clark also outlined, in detail, which sections of the OIA the department could rely on to withhold, in full, the material from Slack.
Emails showed DOC proceeded with its intention to release, with material exported from Slack to Microsoft Excel spreadsheets.
Mr Clark then emailed DOC's lawyer, on 6 April: "I have spoken to Harry about information on Slack and it has also been brought to my attention that [Slack channels] may be released in their entirety.
"Our methodology needs to be protected to ensure that we can continue to provide this service to DOC," Mr Clark said.
Then, two weeks later, DOC's final 20 April response to Checkpoint's OIA request did not mention Slack, let alone include any material from it.
The sections of the OIA Mr Clark outlined in March were ultimately used as justification.
The State Services Commission is investigating Thompson and Clark over allegations state insurer Southern Response hired the firm to spy on Christchurch earthquake claimants, and allegations the Ministry of Business Innovation and Employment hired the firm to spy on Greenpeace.
Prime Minister Jacinda Ardern said in March that Thompson and Clark's "behaviour around spying is totally inappropriate".
Mr Clark has not commented publicly, but in his 28 March email to Mr Maher said that Ms Ardern was "ill-informed" and criticism of his company was a "witch hunt".
Mr Clark today again declined to be interviewed, saying he believed Checkpoint's reporting was "misleading and disingenuous".
The Department of Conservation also declined to be interviewed, but said in a statement it "carefully considered what should be released under the Official Information Act" but did not want to comment while the Ombudsman is investigating.
[h]DOC staff tried to "hide" information from Checkpoint
Before Checkpoint received its Official Information Act response, DOC lawyer's asked Mr Clark for suggestions on what information should be redacted.
Back and forth emails ended with Mr Clark asking which of his at least 10 changes were adopted.
"All of them at this stage," the lawyer replied.
DOC staff also tried to "hide" information from Checkpoint.
"Let me know if you'd like to change the presentation … Perhaps hide the raw analysis?" a staff member emailed Mr Maher, discussing how much DOC paid Thompson and Clark for its services ($103,187 excluding GST since 2015).
And while Checkpoint received its OIA response late, Mr Clark received it on deadline, three days in advance.
"Please keep this letter confidential as it has not yet been provided to the requestor," DOC's lawyer emailed Mr Clark on 17 April.
Mr Clark was also given un-redacted copies of the material released to Checkpoint under the OIA.
"This would assist us in understanding what was redacted and on what grounds and further develop our understanding of the OIA," Mr Clark's email request to the lawyer said.
"For your information only," DOC's lawyer replied, sending through 19 pdf files, "I hope it will assist you".