Local media said Friday that Mutharika had died of a massive heart attack the day before, but there was no official confirmation. The Malawian newspaper Nyasa Times, along with the BBC and Reuters, cited medical and government sources as confirming that the former economist and World Bank official was dead.
The Nyasa Times reported that Vice President Joyce Banda would address the nation and be sworn in as president. Under the country's constitution, Banda would serve out the remaining two years of the president's term and appoint a new vice president.
The government confirmed Mutharika had been hospitalized. However, there was no official confirmation of the 78-year-old president's death.
As the official silence persisted, speculation mounted that Mutharika's inner circle might try to keep Banda from taking office by convening parliament and forcing through a change in the constitution.
Banda was thrown out of Mutharika's ruling Democratic Progressive Party when she opposed his efforts to have his younger brother, Foreign Minister Peter wa Mutharika, named as the ruling party's candidate for 2014 elections. She formed her own political party.
Any effort to resist the constitutional requirement that the vice president take power could spark a constitutional crisis and intense pressure from Western donors.
The tiny southern African nation of about 13 million people is highly dependent on foreign aid and is already suffering from cuts in donations, a decline in foreign currency earnings and disastrous fuel shortages.
President Mutharika had grown increasing unpopular in recent years, as the economy declined. Police killed at least 19 people in anti-government protests last year, a move which cost it $350 million in U.S. aid.
The president, under increasing pressure from critics to resign before the end of his term in 2014, said recently that Western donors could "go to hell."
Last month, the government banned journalists from insulting the president, with Mutharika angered by nicknames like "Mr Know-it-all" and "The Big Kahuna" circulating in the media and on the Internet.
Malawi's crisis deepened after a diplomatic spat last year when Mutharika expelled the British ambassador, Fergus Cochrane-Dyet, following a leaked diplomatic cable quoting the envoy as criticizing the president's increasingly autocratic manner. In response, Britain canceled its support for Malawi's budget, throwing Malawi's hospitals into crisis.
Banda, the vice president, is regarded as a strong advocate of empowering women. She has said that dynastic chieftains were the country's biggest problem.
Reuters reported that there was little mourning in the capital, Lilongwe, over Mutharika.
"I am yet to see anyone shedding a tear for Bingu," said Martin Mlenga, a businessman, according to Reuters. "We all wished him dead, sorry to say that."
-- Robyn Dixon
Photo: Malawi President Bingu wa Mutharika waves to supporters in Lilongwe during an electoral campaign in May 2009. Credit: Amos Gumulira/ AFP/Getty Images