Malawi's President Bingu wa Mutharika has died after a heart attack, doctors who treated him have said.
The doctors said the 78-year-old died on Thursday and his body was then flown to South Africa.
The Malawi government has so far issued only a brief statement on state radio and television, saying Mr Mutharika was taken ill and was flown to South Africa for further treatment.
A Cabinet minister said announcing the death required taking political steps. He did not elaborate, but questions over succession are likely to be complicating matters.
Under the constitution, vice president Joyce Banda should take over. But she has clashed with Mr Mutharika. She was expelled from his party and formed her own, but she remained vice president.
Mr Mutharika's predecessor and former mentor Bakili Muluzi decried the official silence on his death and on the nation's political future. "The present scenario where the government's machinery is almost silent on the health status of our president is very unfortunate and ought not to continue," Mr Muluzi said at a press conference.
"It is the constitutional duty and indeed good practice of the government to inform its citizens and the world community timely, accurate and transparent information about the particulars of the ongoing treatment and health condition of their state president."
When Mr Mutharika first came to power, he was backed by Mr Muluzi. But a feud ensued after Mr Mutharika had Mr Muluzi charged with corruption and fraud.
Mr Mutharika left the ruling party to establish his own. Political bickering between the two men led to extensive legislative delays, rioting, a failed impeachment bid, and accusations of coup and assassination plots.
Mr Mutharika is a former World Bank official once heralded for his stewardship of a southern African country that is among the world's poorest. In recent years, he has been accused of trampling on democratic rights. Mr Mutharika first came to power in a 2004 election, and was overwhelmingly re-elected five years later. Elections are not due again in Malawi until 2014.