TOKYO — MANY Japanese liberals and leftists maintain a vigil over their government, watching for indications that officials are reviving the stifling authoritarianism of prewar Japan.
They apparently have an unlikely ally in the leader of the religious group Aum Shinri Kyo, which has been accused of a series of crimes including the murderous use of nerve gas against Tokyo subway riders in March.
Group founder Shoko Asahara, who has been denying the group's culpability since his arrest in May, has reportedly begun reversing himself out of concern that the government will invoke a Draconian security law against Aum Shinri Kyo. Press reports late this week say that Mr. Asahara has begun acknowledging the group's responsibility for a number of crimes and may be admitting his own role.
Asahara appears to be trying to preserve his group, but many Japanese have criticized the government for even thinking of using the 1952 statute, which has thus far only been invoked in the cases of individual radicals. Religious leaders, rights activists, lawyers, and politicians have said the law's application in this case would be inappropriate and could ultimately lead to its use as a political weapon.
Prime Minister Tomiichi Murayama this week urged bureaucrats to be cautious in deciding whether to invoke the Subversive Activities Prevention Law, but has not blocked their preparations. Although the premier heads the Social Democratic Party, his stance is not nearly as negative as that of his fellow Socialists, who have long opposed the law on the grounds that it inhibits constitutional freedoms of speech and assembly.
If the government goes ahead, Aum Shinri Kyo - whose name means Supreme Truth - would be immediately disbanded and forced to dispose of its assets.
As it is, many of its members are awaiting trial on a variety of charges including indiscriminate murder and illegal confinement of disaffected followers. Authorities say the group was assembling a military force capable of overthrowing the government.
Yoshiro Itoh, a Tokyo lawyer who represents the families of Aum followers, has a more practical objection to the use of the anti-subversives law. ''If Aum is disbanded under this law,'' he says, ''followers are likely to go into hiding and engage in underground activity, and that would be dangerous.''
He adds that it would then be harder to find and deprogram Aum members.
The government is also proceeding with an attempt to disband Aum under a law on religious organizations, but this process would take years and allow the group to continue many of its activities.
Some Aum members have already been convicted on minor charges and others have reportedly confessed to some crimes, but Asahara has until now denied any illegal activity by the group. News agencies quoted his lawyer saying that police investigators had threatened that the government would use the anti-subversives law unless Asahara began cooperating.
After news reports of a confession appeared Oct. 4, Aum Shinri Kyo released a statement saying any such statement would have had to have been coerced and would be worthless in court. The first of Asahara's several trials will begin Oct. 26.
The potential use of the anti-subversives law is not the only aspect of the Aum investigation that some Japanese find troubling. Another is the control that police maintain over the information available about the investigation of the group and its followers.
Amnesty International has repeatedly criticized the Japanese justice system because it allows a long period of detention before indictment - up to 23 days - and relies so heavily on confessions. The rights group says these factors sometimes result in police coercion. But in the Aum cases, says Makoto Iwai of Amnesty's Japanese branch, it has been impossible to assess police performance because there are no sources of independent information about the conduct of the investigation.
The Japanese media have published and broadcast volumes of material about what Aum suspects have told police, virtually all of it dispensed by police in closed-door briefings with reporters. The foreign media are barred from most of these sessions. Critics have accused the authorities of manipulating public opinion by generating negative press coverage of Aum.
An official of the Japan Federation of Lawyers Associations agrees with Amnesty. ''Because there is so little information about what the police are doing, we haven't been able to comment'' on the investigation, says the official, who asked to remain anonymous.
The Federation has long opposed the anti-subversives law, and its president has urged that its application in the Aum case be handled carefully.
The official adds that police have leaked material from their investigation and then shown the resulting stories to suspects in order to pressure them to confess. The Tokyo police yesterday refused to comment on their investigation.