Seoul  - What is Kim Jong Il's true state of health? North Korea's eccentric leader is the subject of speculation yet again. According to South Korean and American intelligence services, he is seriously ill and may have suffered a stroke.

North Korea has denied reports that Kim is ill; a high-ranking North Korean diplomat was quoted by the Japanese news agency Kyodo as saying they were part of a conspiracy.

Pyongyang, however, has not explained why Kim has not appeared in public for weeks and was absent from official celebrations on Tuesday marking the 60th anniversary of the Communist state.

Kim's absence has not only raised questions about his health but also about who could succeed him if he is incapacitated or dead.

Reports of Kim's alleged illness have prompted the South Korean government to prepare for a possible power struggle in the North.

Against the backdrop of difficult negotiations aimed at halting Pyongyang's nuclear weapons programme, observers are warning of greater instability on the divided Korean peninsula should Kim no longer have complete control of his closed regime.

Intensifying the uncertainty is the question of succession.

For years, North Korea has persistently remained silent on this issue, and there have been no signs to date that it has been resolved. Kim was 33 when he was designated to succeed his father, "Eternal President" Kim Il Sung, who was 62 at the time. Kim is older than that now.

Long before his death in 1994, Kim Il Sung systematically groomed his son to succeed him. Many experts doubt, however, that the Stalinist-style state will see another dynastic succession.

"A collective leadership controlled by the military is more likely," remarked Yoon Dae Kyu, director of the Institute of Far Eastern Studies at Seoul's Kyungnam University.

But Yoon said it was premature to come to conclusions about Kim's state of health, pointing out that it was not unusual for him to disappear for weeks from public view.

South Korea's intelligence service believes that Kim has resumed his grip on power despite his illness.

North Korea, experts say, may now be forced to discuss its plan for succession. The country is faced with myriad problems both domestic and foreign, including economic instability and widespread poverty in addition to the nuclear dispute.

Since little information escapes Pyongyang's ruling inner circle, speculation about Kim's successor is likely to continue. More than two years ago, South Korean media reported that Kim had banned all public discussion of the matter.

Kim has three known sons, mentioned over the years as possible heirs by foreign observers. Experts believe that the eldest, Kim Jong Nam, 37, fell out of favour with his father several years ago when he was discovered in Japan with a fake passport.

The other two sons, Jong Chol, 27, and Jong Un, 24, are probably too young to be presented as Kim's successor, Yoon said. (dpa)