Mansour Leghaei, an Iranian religious leader, is fighting deportation after living in Australia for 16 years.
Supporters have launched a campaign to keep him in the country, travelling with him from Sydney to ask the Australian parliament in Canberra to overturn its order for him to be deported.
The Australian intelligence agency said it does not have to disclose any evidence against him.
Al Jazeera Azhar Sukri reports.
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