Adam Brookman, 39, voluntarily returned to Australia from Turkey on Friday. Brookman has told media that he was able to escape from Syria after winning Islamic State militants' trust by working for them in a hospital controlled by the group at al-Bab in Aleppo province.
He appeared briefly in the Melbourne Magistrates Court charged with performing services to help someone engage in a hostile activity in a foreign country.
His lawyer Rob Stary told Magistrate Jelena Popovic that his client would not apply for bail.
Brookman did not enter pleas or speak during his court appearance.
Popovic remanded Brookman in custody until November 16, while prosecutors compile a case against him.
Stary told reporters outside court that police did not consider the Muslim convert and father of five a threat in Australia.
Brookman surrendered to Turkish authorities in Turkey last Tuesday and returned with an Australian police escort to Sydney where he was arrested.
Brookman told Fairfax Media in May that he went to Syria last year to do humanitarian work for civilians caught in the war. He said he was innocent of any crime and was forced to join Islamic State militants after being injured in an airstrike and taken to a hospital controlled by the group.
