Roberts-Smith has not been criminally charged.
Roberts-Smith had made claims of defamation against The Sydney Morning Herald, The Age and The Canberra Times over their articles.
Roberts-Smith is one of several Australian military personnel under investigation from Australian Federal Police for alleged war crimes in Afghanistan.
His return to Australia comes on the same day as reports that an Australian Federal Police investigation into his alleged war crimes had collapsed, Nine News reported.
The decision by the Commonwealth Director of Public Prosecutions not to prosecute Roberts-Smith based on evidence colleted by the AFP probe has led to a new joint taskforce being set up to investigate alleged executions.
- Additional reporting by AP