A Federal Court judge has ordered that a key witness in defamation proceedings involving decorated soldier Ben Roberts-Smith will be allowed to have her identity suppressed over fears for her safety.

Mr Roberts-Smith is suing The Age, The Sydney Morning Herald and The Canberra Times over a series of articles published in 2018 which he says are defamatory because they portray him as a war criminal during his time serving with the Australian special forces in Afghanistan.

Ben Roberts-Smith pictured in 2017. Credit:Darrian Traynor

The articles also portray him as a "hypocrite" who "abused a woman", Mr Roberts-Smith says, by detailing allegations that he punched a woman with whom he was having an affair.

Mr Roberts-Smith, a Victoria Cross recipient, denies the allegations.