Waitemata District Health Board is seeking a court order to permanently monitor a mental health patient accused of murder when his decade-long time limit for detention lapses.
Martin Robert Lyall has been kept at forensic psychiatric unit the Mason Clinic as a special patient after he fatally stabbed Kevan Newman in West Auckland in 2005.
A special patient order keeping him at the unit for a maximum of 10 years expires in December.
Restricted patient orders are very rare - only eight patients have ever been classed as such, but the Waitemata DHB said its doctors believed it was appropriate in Lyall's case.
Waitemata DHB said it had asked the Ministry of Health's national director of mental health to apply to the court to change Mr Lyall's status from a special to a restricted patient in order to keep him under the care of the Mason Clinic.
Auckland Regional Forensic Psychiatry Services clinical director Jeremy Skipworth said this was the only option.
"Changing Mr Lyall's status from a special patient to a restricted patient is the only mechanism available by law to retain a similar level of clinical and administrative oversight to that which he receives currently as a Special Patient," he said.
The Ministry of Health was now looking at the possibility of applying for a court order.
Without the order Mr Lyall's care would be managed under a compulsory treatment order, which meant there would be no oversight from the Ministry of Health's Director of Mental Health or the Minister of Health, Dr Skipworth said.
The seeking of a restriction order is rarely undertaken, with - only eight patients in the country have been given this status, Dr Skipworth said.
"But it is the opinion of our expert clinicians that it is appropriate in Mr Lyall's case," he said.