Kim Jong-il, the enigmatic despot who runs communist North Korea, may have undergone major surgery last month in an operation performed in secret by German doctors.
Reports of a heart bypass operation and failing health have thrown intelligence agencies in the US, China and South Korea into a state of high alert as the region contemplates the prospect of a leaderless, but nuclear-armed, North Korea.
Sources close to the regime say that its 65-year-old dictator was treated successfully for a blocked artery early last month. The German Heart Institute in Berlin confirmed it had sent a team of doctors to Pyongyang in May, but said that they were there to treat patients other than Mr Kim.
There have been persistent rumours that Mr Kim's health is in sharp decline, fuelled by a reduction in the number of his public appearances.
Michael Breen, a biographer of Mr Kim, said speculation was inevitable because of the "huge importance" of the leader's role in the stability of the region. "So much hinges on the health of this one man. It is of enormous significance to the peninsula if he dies. It could be the beginning of the opening of North Korea or the start of a period of profound instability," he said.