Australia's most decorated war veteran Ben Roberts-Smith was "complicit in and responsible for the murder" of three Afghan men on deployment, a judge said Monday, elaborating on his finding against the former SAS special forces corporal in a blockbuster defamation trial.

The judge said Roberts-Smith, holder of the Victoria Cross and other top military honors, was also "not an honest and reliable witness in ... many areas" and a bully toward other Australian soldiers, Federal Court Judge Anthony Besanko said in his full judgment released Monday.

Besanko on Thursday threw out Roberts-Smith's defamation case against three Australian newspapers which had accused him of unlawful killings in Afghanistan. Besanko said the media outlets had proven substantial truth in their reporting, ending a case that lifted the veil of secrecy over the elite SAS.

Australian civil courts require a lower threshold to prove accusations than criminal courts do. Roberts-Smith has not been charged with any offenses and has not commented since the ruling. His lawyer was not immediately available for comment. Roberts-Smith has since quit his job as a television executive.

Besanko delayed releasing reasons for his judgment until Monday to allow the Australian government time to ensure it did not inadvertently divulge national security secrets.

"I have found that the applicant (Roberts-Smith) was complicit in and responsible for the murder of EKIA56 ... in 2009 and the murder of Ali Jan at Darwan on 11 September 2012 and the murder of the Afghan male at Chinartu on 12 October 2012," Besanko said in his 736-page civil court judgment.

Roberts-Smith was accused by the newspapers of ordering a lower-ranking soldier to shoot dead an "older Afghan male," identified in the case as EKIA56, to "blood the rookie," he said.

In addition, Besanko said: "I find that in a compound in Chinartu ... the applicant, through an interpreter ordered (an un-named person) to shoot an Afghan male who was under detention."

A soldier who was there "shot the Afghan male in circumstances amounting to murder. The applicant (Roberts-Smith) was complicit in and responsible for murder," the judgment said.

Besanko found Roberts-Smith engaged in a "campaign of bullying" against another Australian soldier, including what he called a "death threat" when Roberts-Smith said: "if your performance doesn't improve on our next patrol, you're going to get a bullet in the back of the head."

He also said Roberts-Smith was not a reliable witness in one of the country's longest-running defamation cases and had reasons to lie.

"The applicant has motives to lie, being a financial motive to support his claim for damages in these proceedings, a motive to restore his reputation which he contends has been destroyed by the publication of the articles and significantly, a motive to resist findings against him which may affect whether further action is taken against him," Besanko said wrote.

"I find that the applicant was not an honest and reliable witness in ... many areas," he added.

Roberts-Smith, 44, was seen as a national hero, with his portrait hanging in the Australian War Memorial, for his actions during six tours of Afghanistan from 2006 to 2012 and military citations.

A 2020 report found credible evidence that members of Australia's Special Air Service Regiment (SAS) killed dozens of unarmed prisoners in the lengthy Afghan war. Only one soldier has been charged.