The Defence Force told the Australian military it had contaminated water at its bases months before it alerted the New Zealand public for the first time, emails released under the Official Information Act show.
The newly released emails also show Defence gave the Australians a heads up, including about investigations at Devonport, before it told the government.
Defence told the New Zealand public about the contamination with long-lasting and damaging PFAS chemicals in firefighting foam, in early December last year.
It told the Defence Minister last August.
But two months before that, in June 2017, its Environmental Services unit emailed the Australian Defence Force saying it was "about time" they conferred about the contamination.
Which really makes you wonder who NZDF thinks they work for: the people who pay their wages, or a foreign power whose values are increasingly hostile to our own.
But in addition to raising questions about their loyalties, this release has also exposed the level of utter incompetence at NZDF. They have an environmental services unit and a gaggle of outside consultants to advise them. But despite that, they apparently didn't know that the foam was illegal until 2017 - when they found out from the media. Someone there really wasn't doing their job. And now the environment is going to pay the price for their muppetry.