A fourth person has died after eating contaminated food at a baptism ceremony.
Beatrice Mthulanyane, 78, was admitted to Leratong Hospital on the West Rand along with 24 other people last weekend.
All those admitted had attended a baptism at the Anglican Methodist Episcopal (AME) Church in Bekkersdal, near Westonaria, on the West Rand.
They were invited by the Rev Peter Tlotleng to celebrate the baptism of his fourmonth-old son, Tlotlo, on Sunday February 4.
Eighty people were affected by the contaminated food, but only 26 were admitted to hospital. The others were treated and discharged.
A 10-year-old girl, Lindi Ndlovu, died on the day of the baptism ceremony. She was buried at the weekend.
Buti Monaemeng, another guest at the baptism, died last Thursday and was buried on Tuesday.
The third victim, 73-year-old Joyce Mvuka, died on Monday.
Yesterday, a church elder, known as Mama Ester, said Mthulanyane had become so ill that she could not move or speak. She was transferred to an intensive care unit at the hospital.
When she was admitted to hospital she was complaining of stomach ache and had been vomiting.
The Lesotho-born woman leaves three children and several grandchildren.
The Westonaria municipal outbreak response team discussed the poisonings this week.
Westonaria's environmental health inspector, Themba Mtshali, said: "We are moving urgently on this one. The issue was not taken seriously at first but it is becoming a national issue."
Mtshali said a spokesman would be appointed to liaise with the community and the media on all developments.