The Australian Embassy in Cairo said its citizen Safaa al-Awadi was a member of the Shia group detained in September for "promoting Shia doctrines". An embassy statement said officials visited the accused in Cairo on 10 October and later while he was being questioned by state prosecutors.
Al-Awadi has joint Egyptian-Australia nationality.
Relatives of al-Awadi, 44, who live in the Australian city of Perth, told reporters al-Awadi hasn’t been to Australia since August.
The accused were also charged with "disparaging Sunni doctrines and the prophet’s companions", "falsifying" the Quran, and receiving funds from "several foreign countries."
Egyptian media reported that al-Awadi and an Egyptian Shia lawyer took part in a talk show in late August on a Saudi-owned religious channel before their arrest. During the program, they reportedly held a debate with a Saudi cleric on the rightful successor to the Prophet Muhammad. The Prophet's succession constitutes the basis of the Sunni-Shiite split.
Egypt's constitution grants freedom of religion to all citizens, but rights campaigners say the country's Shias face systematic police harassment.
Al-Awadi, who has been detained for nearly three weeks, received another 15-day hearing postponed on Wednesday.