Justice advocates have urgently called on the South Australian Department for Correctional Services to address the "dire concerns" raised by the family of Tony Smith, an Indigenous man now hospitalised due to being on a hunger strike following his transfer from Yatala Labour Prison to Port Augusta Prison in South Australia.

The National Network, a restorative justice advocacy alliance said on Sunday evening that the "pressing fears" of Mr Smith's family "highlight the critical need for immediate intervention to prevent another tragic Aboriginal death in custody".

Network member and chief executive of Sisters Inside, Debbie Kilroy, said Mr Smith's family, including his partner and three children, are "desperately worried" for his wellbeing.

"They have received no information from the Department about his current health or welfare, leaving them to advocate tirelessly on his behalf, desperately seeking information," she said.

"Relocating prisoners to a prison from the city to a regional area, which involves a family making a twelve-hour round trip to visit their partner and father, puts undue financial and emotional strain on a family. This understandably results in the prisoner having fewer visits. Research overwhelmingly indicates that people in prison fare a lot better with connection to family.

"Tony has been in prison since he was 19 years old and has spent more than seven years in solitary confinement. This man has been consistently denied his basic human rights.

Ms Kilroy said the prison system will not give a reason for Mr Smith's relocation, nor respond to the concerns of the family, which she described as "just another assault by the prison system".

"Today, the National Network has spoken with Tony's family, including an Aboriginal Elder who is working to support the family, to discuss how best to support them during this challenging time," she said on Sunday.

"Too often, women and children bear the burden of fighting for justice for their loved ones in such cases. Tony's partner and children are no exception, left to pick up the pieces and advocate for his rights.

"We don't want to see Tony become another death in custody. The Minister of Corrections needs to step in, if they do not, a death could well be on their hands."

The National Network urged the SA Department for Correctional Services to provide transparent information about Mr Smith's current health and welfare to the family and to take immediate steps to ensure his rights and wellbeing are upheld.

"His family and community demand urgent action to prevent another avoidable death in custody," the Network said in a joint statement.

A South Australian Department for Correctional Services spokesperson told National Indigenous Times: "Under section 85C of the Correctional Services Act 1982, we are unable to disclose information on an individual prisoner, so we cannot provide a comment."