Malawi President Bingu wa Mutharika 'dead'

President Bingu wa Mutharika of Malawi has died, doctors and cabinet ministers have told the BBC, but this has not been officially announced.
One of the doctors who treated Mr Mutharika, 78, said the president was "clinically dead" on Thursday after suffering a cardiac arrest.
State media are still reporting that he has been flown to South Africa for medical treatment.If confirmed, his death would spark a constitutional crisis, analysts say.