Malawi’s president was taken to hospital in the country’s capital and will be taken to South Africa for further treatment, state media reported.
The brief statement read on state radio and TV did not say what was wrong, nor say when 78-year-old President Bingu wa Mutharika would travel to South Africa, which has among the best hospitals in the region.
Earlier, officials said Mr Mutharika had a heart problem and was taken to a Lilongwe hospital.
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.
During his first term, Mr Mutharika persisted with a programme to help farmers buy fertiliser even though Western donor nations and agencies said subsidies should be avoided in a free market.
His subsidies were credited with boosting Malawi’s economy.
In more recent years, the economy has stumbled, with shortages of fuel and foreign currency and high unemployment.
Anti-government demonstrations across Malawi last year were met with an unprecedented security crackdown that resulted in at least 19 deaths.
Malawi’s relations with foreign donors have been strained by accusations Mr Mutharika is authoritarian and responsible for human rights abuses.
Last month, a US aid agency that rewards good governance suspended $350m worth of assistance to Malawi.
Mr Mutharika also has clashed with politicians at home, including his own vice president, Joyce Banda.
She was expelled from Mr Mutharika’s party and formed her own but remains vice president. Under the constitution, she would become president if there were a sudden vacancy at the top.