The Judicial Inspectorate of Correctional Services (Jics) revealed that there has been under reporting of deaths that occur in South African prisons since the end of 2017.
The organisation briefed the media this morning when it revealed that suicides by mentally ill patients were on the increase, and other deaths also occurred.
The judicial inspectorate said there was a lack of an adequate and functional mandatory reporting system in the Department of Correctional Services.
The judicial inspectorate's inspecting judge for correctional services, Justice Johann van der Westhuizen said mandatory reporting was an essential function of the organisation and oversight body.
He said an operational challenge is the dysfunctional mandatory reporting system.
He said the Department of Correctional Services has neglected to comply fully with the Correctional Services Act 111 of 1998.
The act required that Jics be informed of the occurrences of any incidents, segregation, mechanical restraint and the use of force.
Jics' report showed that 1200 inmates were identified as being diagnosed with one or other form of mental illness during the 81 inspections which were conducted by Jics inspectors.
"A majority of these inmates are treated at the centres and kept with the general inmate population without adequately trained mental care."
The report also revealed that correctional services facilities in South Africa are overcrowded and in bad condition.
In some instances, there were concrete bricks from the walls, which could be used as weapons.
Beds in some cells were also removed because ceilings were damaged.