The Zimbabwean government has denied reports that President Robert Mugabe is receiving emergency medical treatment in Iran.
South African broadcasters stated that Mr Mugabe had taken ill on a trip to Cuba and had flown from Havana to Tehran.
But Zimbabwe's ambassador to Cuba, Mr Jevan Maseko, said Mr Mugabe is "very strong and healthy," the state Heraldnewspaper reported.
He said South African and western media repeatedly peddled false reports on Zimbabwe. "They are trying to deceive the people of Zimbabwe and cause despondency," he said.
Mr Mugabe (79), who travelled to Cuba on Sunday for a UN environment convention, is expected to return to Harare.
Worsening economic hardships and controversy over stalled talks between the ruling party and the opposition Movement for Democratic Change to negotiate an end to the country's political and economic crisis have led to intense speculation on a possible ruling party successor to Mr Mugabe.
He has led the southern African country since its independence from Britain in 1980.