Victoria Cross recipient Ben Roberts-Smith has started appeal proceedings in the case he brought against his ex-wife over allegations she accessed confidential emails.
The decorated veteran lost his case against Emma Roberts last month and was ordered to pay her legal costs.
A separate defamation trial brought by Mr Roberts-Smith against three newspapers and three journalists is currently underway, with Ms Roberts called as a defence witness earlier this week, finishing two days of evidence on Tuesday.
He denies allegations of unlawful killings in Afghanistan, bullying and domestic violence published in the Sydney Morning Herald, The Age and The Canberra Times in 2018.
In his January 21 judgement of the case between Mr Roberts-Smith and Ms Roberts, Justice Robert Bromwich said the former soldier claimed his ex-wife accessed the email account of their RSGroup company to obtain information to give to legal representatives of the media outlets he was suing for defamation.
Mr Roberts-Smith further alleged Ms Roberts's best friend Danielle Scott and her husband Darren Pill might have accessed the email account as well.
"The crux of all this is that Mr Roberts-Smith believes that the notice to produce in the defamation proceedings was informed by confidential information of his that was provided to the respondents in those proceedings by Ms Roberts, despite the respondents not producing any such material provided to them by her," Justice Bromwich said.
The judge said he found many of the assertions related to Ms Roberts and Ms Scott were ill-founded.
"The threads of material relied upon in relation to Mr Pill do not even rise to the level of a bare prima facie case," Justice Bromwich said.
In the application for leave to appeal, Mr Roberts-Smith's lawyer argues the judge failed to consider or give sufficient weight to the fact that the email account was "frequently accessed from several IP addresses to which (Danielle) Scott and her husband Darren Pill had access".
The lawyer also argues the judge failed to consider that several emails in Mr Roberts-Smith's email were flagged, including a legally privileged email, saying he had not done this.
"The primary judge took into account an irrelevant consideration by suggesting that the Applicant (Mr Roberts-Smith) was intending to conduct an impermissible wider-ranging inquiry during any examination of the First Respondent (Ms Roberts) in circumstances where no such intention was conveyed," the application said.
"If leave (to appeal) is not granted, substantial injustice will be caused to the Applicant."
A date is yet to be set by the court as to when the matter will be heard.
