High-profile journalists Peter FitzSimons and Laura Tingle have been called to provide evidence, amid an ongoing legal battle between Bruce Lehrmann and key segments of the media.
Subpoenas have been filed for the pair to provide documents to the Federal Court.
Another subpoena to the Department of Parliamentary Services (DPS) may explain why it is unable to provide complete CCTV footage of the night Mr Lehrmann was accused of raping Brittany Higgins in Parliament House in March 2019.
Mr Lehrmann is suing the ABC, Network Ten and journalist Lisa Wilkinson for defamation over news broadcasts relating to the allegation.
He denies the allegation and maintains the pair, who worked for Liberal Senator Linda Reynolds at the time, never had any sexual interaction.
Sue Chrysanthou SC, who is representing Ms Wilkinson, told a Federal Court hearing on Friday she is "very concerned" the DPS said it does not have complete CCTV footage of the night.
She noted parts of the footage had been broadcast by Channel Seven in recent weeks.
The case against Ten and Wilkinson relates to an interview she did with Ms Higgins on The Project in February 2021.
FitzSimons, a Sydney Morning Herald columnist who is married to Wilkinson, faces questions over a $325,000 book deal offered to Ms Higgins in 2021.
Publisher Penguin Random House has also been subpoenaed about the deal.
Mr Lehrmann is also suing the ABC for defamation over a National Press Club broadcast featuring a joint speech by Ms Higgins and former Australian of the Year Grace Tame in February 2021.
Tingle hosted the Press Club broadcast and is chief political correspondent for the national broadcaster's 7.30 program.
While the Press Club address never named Mr Lehrmann directly, he claims he was defamed because it invited viewers to speculate about the identity of the person accused.
A separate lawsuit brought against News Corp and journalist Samantha Maiden settled last month with the publisher paying part of Mr Lehrmann's legal costs but not being required to pay him any damages.
His rape trial in the ACT Supreme Court was derailed by juror misconduct.
Prosecutors decided not to pursue further action, citing concerns of the impact it may have on Ms Higgins' mental health.
The ACT government launched an inquiry into how the justice system responded to Ms Higgins' allegations.
A report is being prepared and will be delivered to Chief Minister Andrew Barr by the end of July.
The defamation cases will be back in court on July 17.
