Bruce Lehrmann is fighting to retrieve a blue Moleskine diary seized by the anti-corruption watchdog, which he says has been shared without his permission.
He is suing federal Special Minister of State Don Farrell and National Anti-Corruption Commissioner Paul Brereton over allegations of mistreatment.
Anti-corruption officials searched the 31-year-old's home in June 2024 over allegations he misappropriated secret documents related to French submarines five years earlier.