The authorities in Japan say the Aum Supreme Truth cult responsible for the 1995 gas attack on the Tokyo underground railway is still dangerous and needs monitoring.
The justice minister, Mayumi Moriyama, said the group still considered its founder, Shoko Asahara, an object of devotion.
Mr Asahara is on trial facing several charges, including ordering the sarin gas attack, which killed 12 people and made thousands ill.
If convicted he could be sentenced to death.
The Aum cult - which has changed its name to Aleph - says it is now a benign religious group. It has an estimated 650 followers living in cult communes and some 1,000 lay members.