A Japanese author of a book on North Korea says Kim Jong Nam, who died in an apparent assassination in Malaysia this week, was opposed to hereditary rule by his family and wanted economic reform.

Tokyo-based journalist Yoji Gomi wrote his book "My Father, Kim Jong Ill, and Me," after interviewing Kim, the eldest son of late leader Kim Jong Il. The book provides a rare view into the family, including North Korea's current leader Kim Jong Un, Kim Jong Nam's half brother.

Gomi said Friday that Kim was a tiny hope for change in the isolated communist regime.

There has been speculation of Pyongyang's involvement in Kim's death. Malaysian police have arrested three people in the case, but it's not known if they have any links to North Korea.