Kim's "secret lover" is in her early 50s and was a dancer with a troupe of the General Association of Korean Residents in Japan when she met Kim during a visit to Pyongyang. They later had a child, the Monthly Chosun reported.

Now in her late 20s and living in Tokyo, Mieko is "pretty and well-dressed, though not as beautiful as her mother, and looks affluent," the magazine said, quoting a Korean-Japanese businessman. He described her as amiable and said she got on well with her half-brother Kim Jong-nam. The two are said to be exchanging e-mail.

Mieko buys gifts every year for her father's Feb. 16 birthday and returns to North Korea to attend his birthday party. A Japanese intelligence source said Mieko was confirmed to have attended last year's party and the one the year before. Japanese police keep an eye on mother and daughter out of concern for their safety, the monthly said.

Officials have reason to worry. The eldest son of Kim Jong-il escaped an assassination attempt on his life in China last year, South Korean intelligence said Monday.

The plot against Kim Jong-nam, which came a few months before a similar one in Austria in November, indicates a growing power struggle in the secretive communist country, they said.

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