Police said Wednesday they have unearthed eight cylinders of hydrogen fluoride, one of the chemicals used to make the deadly nerve gas sarin, on a mountainside in Nikko, Tochigi Prefecture, after piecing together tips from former Aum Shinrikyo members.
Investigators believe the cylinders, containing about 160 kg of hydrogen fluoride, were hidden by Aum members following raids on the cult's facilities across the nation that started on March 22, 1995. The police raids took place two days after the Tokyo subway sarin attack, for which members of Aum have been accused.
Hydrogen fluoride is designated as a deadly substance under a law on poisons. A large amount of the chemical was also confiscated from the cult's former compound in the village of Kamikuishiki, Yamanashi Prefecture, during the raids.
In July 1995, police were able to locate other substances used to make sarin, such as phosphorous trichloride and phosphorous trimethyl, based on the confession of senior cult figure Tomomasa Nakagawa. Police sources said about 1 kg of the hydrogen fluoride found near Nikko was used for Aum's development of laser weapons. They said police suspect the substance was purchased by Aum around 1993 and that about 10 cult members buried the cylinders on the mountain.