Authorities have decided to permanently preserve trial records of criminal cases involving the Aum Shinrikyo doomsday cult as part of efforts to prevent a repeat of the serious crimes committed by its members, Justice Minister Yoko Kamikawa said Friday.

"Their crimes were unprecedented, and similar crimes should never happen again. It is my important duty to stop (the records) from being discarded while ensuring they are passed down to future generations," said Kamikawa, under whose orders all 13 Aum death-row inmates, including founder Shoko Asahara, were executed last month.

It is extremely rare for the ministry to announce which criminal cases will have their trial records permanently preserved.