Wayne Morrison was allegedly involved in an altercation which injured five prison officers at Yatala Labour Prison on Friday.

Mr Morrison's sister, Latoya Rule, said the young fisherman and artist was brain dead in the intensive care unit of Royal Adelaide Hospital.

"They said my brother is going to die. I just went to see him, I miss his voice, he has bruises all over him by the police restraining him," she posted to Facebook.

"He has a young daughter who will now grow up without a dad, nephews who will grow up without their uncle Wayne and an entire family that will grow up without their cousin, nephew, brother and son."

The incident occurred in the prison's admissions area while Morrison was waiting for a scheduled court video link appearance, according to SA Correctional Services chief executive David Brown.

Mr Brown said two of the officers received facial injuries, including fractures.

The five officers, who were "shaken up" by the incident, have been discharged from hospital but will be receiving ongoing psychological support.

"I personally, and the officers in my department, understand and take very seriously our responsibility when force is used to bring a situation under control," Mr Brown told reporters on Saturday.

But Ms Rule described her brother as non-violent, claiming he had been denied requests for medical treatment.

"My brother was brutalised by prison officers in custody and did not receive health care from the beginning of his only six days in remand despite requesting it as he was assaulted by white people when he was arrested," she said.

It is understood Morrison's family is planning protests over the incident this week.

"This is not just another death in custody, this is state sanctioned brutality in the same stream as #blacklivesmatter and deserves the same level of attention," she said.