An Australian man travelled to Afghanistan to try to join the Taliban but returned last year because the Islamic militants would not take him seriously, leaked US intelligence documents show.
Material stolen by fugitive US security contractor Edward Snowden is said to show how one of Australia's defence spy agencies monitored conversations on Facebook between the man and his Australian girlfriend - then handed the material to Washington.
The Washington Post reported yesterday an unnamed Australian citizen raised by Afghan parents flew to the war-ravaged country in 2012 "in search of the Taliban".
The Australian Signals Directorate - at the time known as the Defence Signals Directorate - gathered volumes of correspondence between the man and his girlfriend in Australia, mostly from the social networking site.
When he flew home to Australia, he was taken into custody by Australian Federal Police but was released without being charged.
The AFP declined to comment on the issue.