SPONSORED | The Gauteng department of human settlements, together with the Gauteng Partnership Fund,.
The brother-in-law, 26, who cannot be named before he appears in court, allegedly locked the 52-year-old inside his home in Coldrigde in Vryburg, North West, for over a week.
When he arrived back home he found the wheelchair-bound man - a former soldier - eating his own faeces.
The man is not being named to protect his young children.
According to a neighbour, at the time of his death the man had old and new wounds as a result of being beaten.
"It's just that this time he killed him. But he always hit him with a panga, hose pipe or sjambok because he says he does not want him to poop on himself and drink his [own] urine," she said.
She said she once reported the matter to the police but police only gave the man a warning.
North West police spokesman Colonel Sabata Mokgwabone said the man was only warned not to assault his brother-in-law, but no case was opened.
The neighbour has also seen the man eating his own waste, but he allegedly explained to the neighbour that he did so because he was starving.
The neighbour said she normally gave the disabled man tea or food when he was not locked up.
"It was difficult to help him because he was always locked inside," she said.
Last week, the 26-year-old apparently locked him up again and upon his return found him eating his own waste.
"On that day, I saw him pushing him on his wheelchair. I asked him where he was taking him and he said he was taking him to the clinic as he was unconscious.
"I asked him if he had hit him again and then he said yes, because he found him eating his own poop again. The man had bleeding wounds on his arm," she said.
According to the suspect's mother, who lives in the same township, the 26-year-old moved in with his brother-in-law to take care of him after his wife died a few years ago.
She said he used to lock him up and go out.
"What my son did was horrible, I knew that he was abusing his brother-in-law but he was also abusing me," she said.
The mother was looking after the deceased's two children, aged 5 and 8.
She said she felt as if God was punishing her, as she did not know how she would provide for the kids now.
"I do not know what is going to happen to those children, their mother died, now my son killed their father, this is like a curse," she said.
Mokgwabone said a case of murder had been opened.
"The suspect will appear in the Vryburg Magistrate's Court on Tuesday [today]," he said.
Postmortem results are pending.