An assisted death at a hospital is being investigated by the Health and Disability Commissioner.
The case was referenced in the first annual report by the Assisted Dying Registrar.
Relatives criticised their experience at an unnamed public hospital to the Ministry of Health.
The complaint was upheld and referred to the Health and Disability Commissioner, who has begun an investigation.
More details remain unknown as the Commissioner's office said it was unable to comment while a case was under active assessment.
The complaint is one of four received by the department from November 2021 up until March this year.
Three of them have already been closed. They were filled by the applicants and were related to personal style communication from the doctor, delay on a connection with a practitioner and and dissatisfaction with the process and outcome.
The End of Life Choice Act took effect in November last year.
The Act came into effect after nearly two-thirds of New Zealanders voted in favour of it in a referendum.
The Ministry of Health report shows since the new legislation took place in November, 206 people applied for it.
From those, 59 people were still in the process of assessment or preparation for assisted dying and 66 people have had one since.
The report stated that 40 people had been assessed as ineligible, being 65 percent of those due to not having a terminal illness likely to end their life within six months.
Eighty percent of those who applied were receiving palliative care at the time.
The Ministry said in the coming year, it will continue to improve the service through working with Te Apārangi and the statutory committees, using feedback and applying any recommendations from the implementation review.
It said quality improvement will provide an opportunity to refine the support provided to people and whānau who engage with the service.
The Ministry said it will seek to undertake collaborative research to deliver an effective, compassionate, person-centred service.
The End of Life Choice Act 2019 will be reviewed.
