Doomsday cult Aum Shinrikyo, which was behind the 1995 Sarin gas attack on the Tokyo subway, is growing and remains a threat, according to the Japanese justice ministry.
In the latest annual review of the cult, the ministry said it was reasserting its influence via the internet.
The ministry said Aum Shinrikyo now had about 650 leaders and teachers and a further 1,000 followers in Japan and elsewhere, and uses the internet and video conferencing to stay in touch.
The group hit the headlines in 1995 after releasing deadly Sarin nerve gas in the Tokyo subway, killing 12 people and injuring thousands of others.
Cult leader Shoko Asahara is in jail
The cult, which changed its name last year to Aleph - the first letter of the Hebrew alphabet - insists it is now a benign religious group.
Noting that it had changed its name and apologised for the gas attack, the report said however that the organisation's "deceptive nature" remained unchanged.
"The sect attempts to conceal its organisational management by using systems such as the internet and video conferencing to relay its orders and manage and teach its members", the French news agency AFP quoted the Justice Minister, Masahiko Komura, as saying.
The report concluded that the group's "dangerous nature has not changed", even though no poisonous substances or ingredients have been found in their facilities.
It noted that Aleph was expanding its computer-related business and making profits from other companies involved in publicising the teachings of its jailed leader, Shoko Asahara.
Since the jailing of Asahara - a half-blind, charismatic man whose real name is Chizo Matsumoto - daily control of the cult has fallen to Fumihiro Joyu, the former head of Aum's operations in Moscow.