Three Defence Force staff were stood down from their roles after the Ministry of Education reported inappropriate behaviour during a training course run by the military for high school students.
Documents obtained by RNZ under the Official Information Act show the ministry told the military about the conduct of staff during a youth course in March last year. The course was held at the Waiouru Military Training Facility in the central North Island.
The unit trains high school students at two bases in activities such as physical training and military procedures, however it said no firearms were used.
The military said there was no formal complaint made by the school - which was not named - or the students, however feedback was provided on 13 August after a survey of the unit's performance.
Two days later, the military informed Defence Minister Ron Mark.
"The allegations made centred around the use of inappropriate language by an instructor," the documents said.
It did not say what language was used, however three Defence Force staff were stood down from instructional duties while an investigation took place.
In addition, in September Defence Force chief Air Marshal Kevin Short wrote to the country's education head, Iona Holsted, assuring her he was addressing the ministry's feedback.
"I note your response contained a number of comments that raise concerns regarding the standard of behaviour of some NZDF instructional staff.
"I take any allegations of unprofessional behaviour very seriously," Mr Short said.
As a result of the investigation, which involved the Military Police, the documents said the three staff were stood down for between one to three months.
"Subject to an assessment that there was no risk to youth or further risk to the NZDF's reputation," Mr Short said.
The military also put all Youth Development Unit staff through further training.
"The commanding officer of the Youth Development Unit instituted refresher training for all staff on the code of ethics, incident reporting and NZDF expectations regarding acceptable behaviour."
The documents went on to say that the school involved remained committed to the course and the ministry and the military had agreed to new processes if similar behaviour happened again.