They were the first raids since the Tokyo High Court last month rejected a document explaining defence arguments in the retrial of Aum Supreme Truth sect founder Shoko Asahara, increasing the likelihood he will be hanged.
Some 160 police officers inspected 11 sect facilities across Japan, including its headquarters in the Tokyo residential district of Setagaya, and questioned members about their activities, officials said.
Justice Minister Seiken Sugiura warned that the bearded cult founder, whose real name is Chizuo Matsumoto, still wields significant influence over the 1600-member sect, now renamed Aleph.
“Their belief in Chizuo Matsumoto appears to be still strong,” Sugiura told a news conference following the raids.
“The number of believers is not declining while activities are still going on,” the minister said. “We still need to be fully on alert.”
Japanese media said the raids aimed to find out if sect members were plotting any actions related to the court proceedings for Asahara, a former acupuncturist who preached an apocalyptic mix of Hindu and Buddhist beliefs.
The cult escaped being outlawed when a legal panel ruled in 1997 that there was no reason to believe it still posed a threat to society.
But after a public outcry, parliament passed legislation allowing police to conduct snap raids and demand information including financial data from the sect without needing a warrant.
In March 1995, the sect sprayed Nazi-invented sarin nerve gas on rush-hour trains, killing 12 people and injuring thousands.
The Tokyo District Court sentenced Asahara, 51, to death in February 2004 for the subway attack and other crimes which claimed a total of 27 lives.