The son of slain Adelaide Crows coach Phil Walsh has multiple sclerosis, faces an uncertain future and should be granted limited release on “humanitarian” grounds, a court has heard.

Counsel for Cy Jacob Walsh on Wednesday urged the Supreme Court to authorise limited, closely supervised release from high-security mental health facility James Nash House.

But Lucy Boord, prosecuting, urged caution given Walsh’s relatively short time in mental health care.

“The prosecution takes a conservative approach when there’s been a long period of stability in someone’s mental state,” she said.

Camera Icon Credit: The Advertiser

“This is not an extraordinarily long period of stability, with the greatest of respect.

“Given that, the prosecution will clearly (advocate for) a cautious approach.”

Walsh, 29, has been held in the secure facility since he was found not guilty, due to mental incompetence, of murdering his father.

He repeatedly and fatally stabbed Phil Walsh inside the family home in 2015 while affected by undiagnosed, untreated schizophrenia.

Prior to the fatal confrontation, Cy Walsh had been a habitual users of hallucinogenic drugs, had brawled with his father in the streets of Perth and spoken of wanting to “rip out” the older man’s heart.

Camera Icon Cy Walsh was found not guilty of his father’s murder due to mental incompetence. Credit: 7 News

Justice Anne Bampton last year ordered that Walsh spend the rest of his life under a limiting term — psychiatric supervision similar to a jail term a mentally able person would receive.

Tiffany Walsh, for Cy Walsh, told the court on Wednesday her client’s circumstances had changed.

“Your Honour would be aware that he was, earlier this year, diagnosed with multiple sclerosis,” she said.

The condition, also known as MS, causes scarring on the central nervous system which can affect muscle control and lead to memory loss, depression and cognitive difficulties.

While there is no cure, treatments exist to lessen symptoms and slow the disease’s progression.

Camera Icon Cy Walsh stabbed his father to death while hearing voices.

Ms Walsh said her client should be permitted to leave James Nash House, in the company of staff, because prison transports were not readily available for medical visits.

She said Walsh’s neurologist had also recommended he be granted supervised “rehabilitation leave” to venture outside James Nash House.

“That’s simply to visit the local area around James Nash House, certainly not to go too far afield,” she said.

“It’s because his prognosis is uncertain and it’s about, in a nutshell, quality of life and humanitarian reasons.”

In a “victim and next of kin” report released by the court last year, Walsh’s mother — and Phil Walsh’s wife — Meredith Walsh revealed how her son’s psychiatric treatment was allowing him to “grieve” his father.

“Mrs Walsh is very supportive of (Cy) and advised her wish is for him to have a ‘normal life’ and not be detained for a significant period of time,” a social worker stated in the report.

“She was hoping that in the future she could move with (Cy) and reside interstate as there was a large family support network outside of South Australia.”

Justice Bampton ordered medical reports and will hear the case again in March.