The director-general in the Presidency, Frank Chikane, has confirmed that Kate Zuma called him on the morning of her death and told him that she had taken the drugs. She died on Friday, December 8, last year as she was being rushed to a Pretoria hospital.
Zuma, who had been married to the Deputy President for 18 years, was given a state funeral that was addressed by President Thabo Mbeki and Nelson Mandela.
The Presidency said initially that Kate Zuma, one of the Deputy President's two wives, had died of heart failure. However, Chikane and the National Police Commissioner, Jackie Selebi, confirmed on Friday that her death was being investigated by the police and that a final post mortem report was awaited, The Sunday Times said.
A preliminary report established that there was an overdose of chloroquine - an anti-malarial drug - in her bloodstream.
On the morning of her death, Zuma, the mother of five of the Deputy President's ten children, phoned Chikane to tell him that she had taken an overdose of malaria and sleeping pills. It is believed she was depressed because of strained relations with her husband.
Chikane confirmed to The Sunday Times that he had received the call from Kate Zuma and had rushed to the Deputy President's official residence in Pretoria, Oliver Tambo House.
He said he immediately called the presidential emergency services and Zuma was rushed to the Muelmed Hospital.
Chikane said he remained at the house and, a short while later, he received a call from the hospital to inform him that Zuma had been declared dead on arrival.
"As the director-general of the office, the health of the President, the Deputy President and their families is my responsibility. It was therefore my task to break the news to the Deputy President that his wife had died," Chikane told The Sunday Times.
Jacob Zuma's spokesperson, Lakela Kaunda, said the Deputy President had been out of town the previous night and had just returned to his office at the Union Buildings when he was given the news.
President Mbeki apparently rushed to Zuma's office within minutes to comfort his deputy.
A Christmas party for presidential staff had been planned for the day and Mbeki, the host, immediately cancelled it.
Chikane said the presidency initially announced that Kate Zuma had died of heart failure on the strength of a report by the Surgeon-General's office. "We had to be careful not to pre-empt the findings of the post mortem. It is true that she died of heart failure but what caused it is a matter of investigation," he said.
Selebi said that if the report declared Zuma had died of unnatural causes, a magistrate would decide whether an inquest should be held.
Kaunda said the Deputy President fully supported police efforts to find out what had happened.