A Japanese daily says North Korean leader Kim Jong-il may have health problems.

The Sankei Shimbun raised the possibility Wednesday, saying that the reclusive leader was not present at a ceremony earlier this month to mark the 13th anniversary of his father, Kim Il-sung's death.

The paper said Kim is likely to have paid his personal respects at his father’s grave separately.

Kim did not attend last year’s ceremony either. However, the paper said Kim's absence last year was likely to have been due to security concerns as the ceremony was held shortly after Pyongyang had test-fired missiles.