This can be issued against any person, not just terrorist suspects. For example, ASIO can question someone about the activities of a family member, a journalist about a source or a priest about what they have heard in the confession box. The person has no right to silence and failing to answer is punishable by five years in jail.

ASIO can also apply for a detention warrant. This allows someone to be held in secret and questioned for up to a week. This could be applied to a journalist who might destroy their notes to protect a source, or a person who might not turn up for questioning so as to avoid talking about a relative.

In detention, a person cannot contact their family, friends or employer. They simply disappear for up to a week. They have the right to a lawyer but their choice can be vetoed on national security grounds and questioning can start before their lawyer arrives.

The person is kept in the dark as to why they are being held. They are not told why the warrant has been issued against them and their lawyer cannot ask questions or intervene in questioning, except to request clarification of an ambiguous question. All contact between the person and their lawyer must also occur in a way that can be monitored.

This whole process is cloaked in secrecy. While a warrant is on foot, and for two years afterwards, it is an offence to disclose ''operational information'' about a person's questioning or detention. The penalty is five years' imprisonment.