The Public Security Investigation Agency inspected 39 Aum Shinrikyo-related facilities in 2004, later sharing pertinent data with 49 municipal governments, according to a government report released Friday.
The Cabinet-approved report states that the agency, which operates under the Justice Ministry, carried out the inspections under the so-called Aum surveillance law.
This legislation allows the agency to monitor any organization that has committed "indiscriminate mass murder in the past."
Some members of the cult have been convicted of involvement in the March 1995 sarin attack on the Tokyo subway system, which killed 12 people and injured more than 5,000.
The law requires the agency to submit to the Diet an annual report detailing the latest activities of the cult, which renamed itself Aleph in 2000.
Justice Minister Chieko Noono told the Cabinet that the government must continue to monitor the cult, which she says "still maintains a dangerous dogma and has not changed its reclusive nature." She also said Aum is still trying to boost its membership.
The report states that, at the end of last year, Aum had about 650 live-in followers and about 1,000 other followers. It maintained 26 facilities in 17 prefectures.
The cult also has about 300 followers in Russia, where it maintains several facilities, the report says.