Two-thirds of teachers at a Bay of Plenty childcare centre had traces of cannabis in their system while at work - with one turning up with bloodshot and "very red" eyes.
Six of nine teachers working at Rotorua's Te Puna Manawa o Whakaue were found to have THC in their system - some 64 times the cut-off.
The September 4 discovery resulted in the voluntary closure of the Te Taumata o Ngāti Whakaue Iho Ake Trust-governed centre on September 6.
Five of the teachers had resigned and one was fired by September 25. The Ministry of Education suspended the centre's licence on October 9.
The Teaching Council confirmed there was an ongoing investigation "into a matter relating" to the incident.
Documents obtained by the Rotorua Daily Post under the Official Information Act outline the tests results and actions taken during and after the day of the incident.
How did it unfold?
Six of the centre's nine staff failed drug tests after a staff member was questioned for his bloodshot and "very red" eyes, and "very fidgity" and "unusually quiet" behaviour on the morning of September 4.
The Puna Manawa team leader asked the staff member if they could privately discuss their behaviour which also included being "late without any explanation" and an "unwillingness to engage with the team leader, staff or tamariki".
"Once we got into my office, I raised my concerns with him. He became nervous and anxious and disclosed to me that he was a regular user and had recently smoked marijuana," the documents stated.
"This staff member admitted they were a regular drug user and there were at least four other staff who were regular drug users."
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The trust's then-general manager Roana Bennett authorised immediate drug tests and five other staff admitted they would possibly fail their tests.
Those six staff members - five of whom were registered, qualified teachers - produced a "non-negative result" and put on "verbal proposed suspension on full pay".
The trust was able to keep Te Manawa Puna open over the following days by employing staff from Te Puna Akoranga, another trust-governed centre which had its licence suspended earlier this year after the Ministry of Education found 47 breaches there .
These breaches focused on safety checking, child protection, mandatory reporting, adult-child ratios, supervision, management practices and information to whānau.
The afternoon of the discovery off-site drug testing took place and produced six "non-negative" results with THC readings from 96 nanograms per millilitre of urine, to 956ng/ml. The cut-off is 15ng/ml.
The Drug Detection Agency chief operating officer Glenn Dobson told the Rotorua Daily Post it was "too dangerous" to read into the numbers because there were many variables which can muddy the waters of a drug test.
"Unfortunately, it is not as simple as saying 900 is high and 200 is low. It could be due to how they ingested it for example,'' he said.
"With cannabis especially, there is also a ratio that is used around the creatinine levels in the urine. So it would be interesting to see if the urine sample was concentrated or diluted."
The main reason behind the 15ng/ml cut-off is to eliminate any external environmental or reasons to why that drug may be present in the person's system, Dobson said.
A Teachers Council mandatory report form, including THC readings, was produced for the five registered teachers and those forms were released under the Official Information Act.
The THC reading of the sixth staff member is not known but that employee was dismissed.
The sixth staff member was sent a series of three letters detailing their suspension, an invitation to a disciplinary meeting on September 12 and the preliminary outcome.
The latter letter outlines the proceedings of the meeting after Te Taumata o Ngāti Whakaue Iho Ake Trust discussed the allegations. The trust considered rehabilitation for the staff member but did not believe that could be progressed.
"You state your belief that despite your result ... you would not have been under the influence while working," the letter states.
"We were advised by your advocate that what you do in your own time is none of our business.
"You're not acknowledging the result as being extremely concerning considering the environment in which you work."
The other teachers also outlined the reasons behind their drug use in the mandatory reports.
A recurring theme was stress and alleged lack of support brought on by the licence suspension and subsequent closure of the trust's other early childcare centre.
One teacher, who had a reading of 956ng/ml, was reported to have been under stress at work for some time, "particularly [due to] the lack of leadership and support".
Another teacher felt "traumatised" after the Puna Akoranga closure. She had a reading of 429ng/ml and was re-thinking her career choice after resigning at her disciplinary meeting, the documents reveal.
Another teacher had a reading of 956ng/ml. She resigned but relayed her "determination to address her addiction issues" so she could return to early childcare, "a career she loves".
A first-year teacher was offered rehabilitation by the trust as it believed the teacher "could have expected a greater level of support and mentoring from the organisation, particularly from the older and more experienced teachers".
This teacher also had a "relatively low reading" of 96ng/ml and showed genuine remorse.
The fifth teacher included in the documents has now found an "alternative to address her anxiety" after a THC reading of 299ng/ml.
In an email sent to Ministry of Education staff on the day of the testing, early childhood senior advisor Gina Royal said she believed the centre had "acted swiftly in this instance to mitigate immediate risk to children".
She said the trust had sufficient numbers of relieving qualified early childcare education staff to accommodate 30 children and the van service had been cancelled on the day of the incident "due to ratios".
But higher up in the ministry, calls were made for immediate licence suspension.
A meeting was held the following day, September 5, and the trust agreed to voluntarily close the service, effective 5pm on September 6, for a period of three weeks and aim to meet a list of regulations before reopening.
These included providing evidence to show the service was effectively governed, taking all reasonable steps to promote the good health and safety of children enrolled, complying with adult-to-child ratio requirements and providing evidence of records and results of safety checks for all children's workers in accordance with the Children's Act 2014.
However, by September 27, the ministry was not satisfied with the capability of the trust to address the licensing regulations and criteria and suspended the licence.
Te Taumata o Ngāti Whakaue were approached for comment.