North Korea's Kim fell seriously ill in April: report

North Korean President Kim Jong-il looks from a limousine window as he leaves Russia's far eastern city of Vladivostok in this August 23, 2002 file photo.

TOKYO (Reuters) - North Korean leader Kim Jong-il fell seriously ill in April, sometimes losing consciousness at work and unable to rule on important policy matters, the Mainichi daily reported on Sunday, citing a "reliable" Chinese source.

The Japanese newspaper said Kim's poor health was apparently behind the lack of flexibility in North Korea's recent attitude towards the six-party dialogue over its nuclear program.

Kim, 66, had been making all decisions on the country's nuclear policy, the source told Mainichi, and after his health worsened there was no one who could make major diplomatic moves.

This raised speculation that hard-line military figures had increased their clout in the leadership ranks.

North Korea's official media had reported no public appearance by the reclusive "Dear Leader" since mid-August, but Kim's failure to attend last Tuesday's triumphal military parade marking the state's 60th anniversary made worldwide headlines.

Speculation swirled that he had suffered a stroke, was gravely ill or even that he had been dead for years and replaced by look-alikes for state occasions.

The following day, North Korea's nominal number two leader, Kim Yong-nam, told Japan's Kyodo news agency: "(There is) no problem".

Senior North Korean diplomat Song Il-ho told Kyodo: "We see such reports as not only worthless, but rather as a conspiracy plot".

The communist state's official media have continued their blanket praise this week for Kim and his late father, state founder Kim Il-sung, with not the slightest acknowledgment that there might be a power vacuum at the summit of the state.

The Korean Central News Agency (KCNA) carried an item on Sunday saying that Kim had sent birthday greetings to Russian President Dmitry Medvedev.

Sunday's Mainichi report said Kim had first complained of problems with multiple organs, including his heart and kidneys, in the summer of 2007 and his condition had gradually worsened.

Citing the same Chinese source, the daily said Kim, who often used to work late into the night and early in the morning, had become unable to do so as his health progressively failed and his judgment deteriorated.

(Reporting by Taiga Uranaka, editing by Roger Crabb)