Malawi President Bingu wa Mutharika was rushed to hospital on Thursday after collapsing and remained unconscious and in a "very serious" condition, medical sources and a diplomat said.
However, government spokeswoman Patricia Kaliati said she was unable to confirm the president had been taken to hospital.
Medical sources told Reuters they were preparing to airlift Mutharika to South Africa as soon as he stabilized.
"He was brought in on a convoy of three cars. His head was covered to hide his face as he was wheeled in on a wheel chair," said one hospital source.
Asked whether Mutharika had been taken into hospital, Kaliati said: "What you are saying is news to me. I was with him this morning and I can tell you that he is alright."
Mutharika, 78, has been president of the landlocked southern African nation since 2004 and presided over more than five years of economic boom, during which Malawi became one of the world's fastest-growing countries.
The growth came to a halt last year after a dispute with Britain led to tit-for-tat diplomatic expulsions and a freezing of millions of dollars of aid.

Source: Reuters