The criminal case involving an international bugging scandal is being heard under a shroud of secrecy.
The ACT Supreme Court heard the case against Bernard Collaery behind closed doors on Wednesday.
Phones were confiscated at the door before the public was later ordered to leave the courtroom as the parties discussed confidential evidence.
Collaery is accused of breaching national security laws by helping his former client, an intelligence agent, blow the whistle on the Australian government tapping the East Timorese government's cabinet rooms as the two countries negotiated an oil and gas deal in 2004.
The matter is due back in court next year with Collaery looking to fight the charges via trial by jury.
But the lead-up to the trial has been bogged in delays, as the parties involved battle it out during separate hearings on what can and can't be heard in an open court.
Collaery intends to call former East Timorese prime ministers Jose Ramos-Horta and Xanana Gusmao as witnesses in the hearing.
He's also called Australia's former Indonesia ambassador John McCarthy, former foreign minister Gareth Evans and former defence chief Chris Barrie to take the stand.
Collaery's former client, known as Witness K, is being prosecuted separately in the ACT Magistrates Court and may be looking to plead guilty.