The four, including former police officer Toshiyuki Kosugi, 39, were arrested in July and later released.

The Tokyo District Public Prosecutor's Office said it has doubts about the credibility of Kosugi's confession. Kosugi changed his statement after being arrested.

The prosecutors and police had continued questioning the four on a voluntary basis after their release.

The three others are Tetsuya Uemura, 49, Mitsuo Sunaoshi, 37, and Koichi Ishikawa, 35. Ishikawa was arrested over an explosion at a religious scholar's house.

The NPA commissioner general at the time, Takaji Kunimatsu, was shot and severely wounded outside his home in Arakawa Ward, Tokyo, on March 30, 1995 -- eight days after the police launched raids on Aum following the cult's fatal sarin gas attack on the Tokyo subway system.

The Japan Times Weekly: Sept. 25, 2004
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