Officials say Mr Mugabe was on holiday, not in hospital
Zimbabwean officials have denied reports that President Robert Mugabe is ill, labelling them the product of "sick and evil minds".
South Africa's Times newspaper claimed that Mr Mugabe was "secretly" whisked away to a Dubai hospital for treatment.
But Zimbabwean officials said the 85-year-old leader was back in the country after a holiday and was in good health.
South African President Jacob Zuma is due in Harare on Thursday to hold talks with Mr Mugabe.
A spokesman for Mr Zuma said the meeting was still scheduled to go ahead.
"We have not received any official communication about President Mugabe's health, as a result our plans have not changed," said Vincent Magwenya.
'Load of rubbish'
The Times reported that Mr Mugabe had been undergoing specialist treatment in the United Arab Emirates.
But Zimbabwean officials strongly dismissed the claims.
"The president is not sick but was away on holiday," Reuters quoted one official as saying.
"He returned home yesterday, and those reports are a load of rubbish that we get from sick and evil minds."
The reports come as Mr Zuma prepares for his first trip to Harare as president.
He is the current chairman of the Southern African Development Community, the body which helped to broker Zimbabwe's power-sharing government.
Mr Tsvangirai's Movement for Democratic Change (MDC) has raised a range of issues with the power-sharing deal, including Mr Mugabe's unilateral appointment of the central bank governor and attorney general.
The MDC said the appointments dishonoured one of the conditions of the government of national unity.