When the New Zealand government imprisoned Ahmed Zaoui for two years without trial on the sole word of the SIS (who refused to give reasons), it was a national scandal. Eventually, after two years of imprisonment without trial he was granted bail. Three years after that the SIS withdrew their security risk certificate on the eve of its judicial review - effectively admitting they were wrong. The process was so shoddy, and the SIS so obviously jumping at shadows, that they have AFAIK never issued another risk certificate.
Not so in Australia. Over there they've just freed 10 people they were holding under a similar law, after the ASIO changed their minds about whether they were a threat. But they continue to hold 34 people without trial and without letting them see the "evidence" against them:
A group of 10 refugees assessed by ASIO as threats to national security have been freed to live in the Australian community after the agency quietly reversed its decision.
Some of the group had been held in immigration detention more than five years without having been charged with a crime under a system civil liberty advocates have slammed as "completely unsatisfactory".
Most of the men have been released since August from a detention centre in Melbourne's north, where the majority of the remaining 34 refugees given a negative assessment by ASIO are still being held.
The same principle which applied to Ahmed Zaoui applies here: freedom or a fair trial. The claims against these people must be heard in open court, so we can see whether they are supportable or whether they are a tissue of spy-fantasies. And if the spies are unwilling to do that, then they must be released.