A mental health advisor has resigned from the Southern District Health Board alleging the controlled drug continues to be prescribed off-label without informed consent, despite two investigations into the practice.
Last year the National Health Board investigated the practice by the Mental Health Service at Dunedin hospital of treating patients with depression with the drug, but its findings have not been released.
Health and Disability Commissioner Anthony Hill has been conducting an investigation into the matter since last October.
It has been alleged ketamine was given to about 10 patients without proper consent or ethical approval.
Graham Roper who left his position as the southern DHB's mental health consumer advisor at the start of this month, says he has evidence ketamine continues to be prescribed off-label.
The Southern DHB insists the use of ketamine as a treatment for depression has stopped for all but two mental health patients who gave their informed consent.