Speculation has not abated over the health of former Prime Minister Noboru Takeshita, who has been hospitalized for nearly a month due to what was described by his aides as back pain.

Four weeks have passed since Takeshita, 75, entered the Tokyo hospital. Initially, his office said he would be hospitalized for "a few weeks."

Reflecting Takeshita's lingering influence over Japanese politics, rumors have surfaced that his illness may be more serious than publicly explained, which could affect plans by Prime Minister Keizo Obuchi -- one of Takeshita's closest disciples -- to seek re-election as Liberal Democratic Party president later this year.