As a successor to Kim Jong Il , analysts have begun looking at the North Korean leader's brother-in-law. But if Mr Jang Song Taek were to emerge on top, it would likely be as the head of a collective leadership, rather than as an absolute ruler like Mr Kim Jong Il or his father, North Korea founder Kim Il Sung, experts in Seoul say.
They say no single person in the communist dictatorship is poised to take over as smoothly as Mr Kim - groomed for 20 years - did after his father died in 1994. But the 62-year-old Jang, husband of Mr Kim's younger sister, is seen as a potentially critical player. Mr Jang heads the administrative department of the all-powerful Workers' Party. More importantly, he oversees the intelligence agency and other military-related institutions, analysts say.
Other senior figures in a collective leadership would likely include Defence Minister Kim Il Chol and other top military and party figures, the analysts said.
The regime's abandonment of the painstakingly crafted disarmament-for-aid deal after steadily disabling the programme since last November has raised speculation that if Kim is ill, the hard-line military is quietly pulling the strings, characteristic of Kim's 'typical brinkmanship strategy' during diplomatic talks.