His Gumboot Fund - an initiative to pay for counselling services for teens on demand - made headlines in October after it exhausted its annual budget in months, sparking concerns from mental health providers that vulnerable young people were having expectations raised then dashed.
A November 8 email from deputy director-general of health Robyn Shearer to King, obtained by the Herald under the Official Information Act, laid out the Ministry's position on whether it would bail out the fund in formal language.
"We take seriously the need for due diligence and the need for appropriate processes to be followed when it comes to the use of public funds," she said.
The letter ended with an invitation "to meet with you and work together".
King this week said he had not followed up on the offer as there was "no point in talking".
A week before that letter was sent - shortly after news broke the Gumboot Fund had exhausted its capacity - an evening email exchange between King and Shearer boiled over.
"While the ministry cannot step in and fund this initiative I am happy to talk with you on how this situation could be managed ... with some new boundaries and extra limitations," Shearer said.
Minutes later, King replied: "Thank you for outlining the [ministry's] position of no funding for the Gumboot Friday initiative ... I'd like to thank you for your very generous offer to help us 'manage the situation' and your advice on next steps, but we'll be fine managing the situation on our own."
King told the Herald this week the exchange had been frustrating. "It's fair to say I was upset - but it really galvanised to me the reason we don't ask for Government funding. We're not Government contractors," he said.
A briefing prepared by the ministry in February reiterated the lack of official involvement in King's activities:
"The Key to Life Trust is now promoting the fundraising campaign for Gumboot Friday 2020, which will take place on 3 April 2020. The ministry has not been asked to be involved. We will be reaching out to the Key to Life Trust again to offer to assist them in ensuring sustainability of the fund and the safety and care for young people."
Questions to the Ministry of Health this week were answered with a statement, confirming the November 8 letter was the last contact with King and his trust.
"The Ministry of Health is not involved with Gumboot Friday... To date, the ministry has not received a funding request from the Key to Life Charitable Trust."
"The Government committed significant funds through the Wellbeing budget to a five-year programme focused on ensuring that people can access free and immediate advice and support that most suits their needs, where and when they need it," the statement said.
King said his Key to Life Trust - which administered the Gumboot Fund and which he said he drew no salary from - had enough reserves to "keep us going for eight months" and any funds raised online on Friday would go directly to funding counsellors.
New Zealand Association of Counsellors president Christine Macfarlane said the Gumboot Fund lacked processes and oversight seen in other publicly-funded counselling initiatives, but while King was a polarising figure he deserved some credit.
"I do applaud Mike for his passion and his ability to keep doing this in the face of so much criticism. It's not an easy place to be standing up and talking about mental health, and he does come up with a different way of looking at it," she said.