Australia’s most decorated living war veteran Ben Roberts-Smith has been spotted leaving Queenstown airport this afternoon - just weeks after allegations he committed war crimes were ruled by a judge as substantially true.

Australian media outlet Nine News have tonight reported Roberts-Smith was spotted boarding a flight from Queenstown Airport - almost two weeks after he lost his defamation case against The Age, The Sydney Morning Herald and The Canberra Times.

Roberts-Smith had spent time in Queenstown with his girlfriend on holiday before boarding a flight understood to be heading to Brisbane this afternoon, Nine News’ A Current Affair program reported.

The Victoria Cross recipient had been noticeably absent from court on June 1, when the judgement in his defamation case was handed down.

Australian Federal Court judge Anthony Besanko ruled that the articles published in 2018 were substantially true about a number of alleged war crimes committed by Roberts-Smith, a former Special Air Service Regiment corporal who now is a media company executive.

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