After a 16-year-old extremist attempted to stab a Bishop at a church in Western Sydney, ABC investigative journalist Sean Rubinsztein‑Dunlop was approached by a man with an extraordinary claim: he was a former undercover ASIO spy who had infiltrated extremist networks in Sydney linked to Islamic State. In this episode of Uncovered, Sean tells the story of ‘Marcus’, the ex-spy who, while undercover, met Naveed Akram and his father, the men allegedly later responsible for the Bondi Beach terror attack. Marcus gathered intelligence, faced life-threatening risks, and witnessed individuals on a path to violence. He says he warned ASIO of Naveed being a potential threat, but authorities disagreed with his assessment. Through Sean’s reporting, we go inside Australia’s hidden world of counterterrorism and see how Marcus’s actions intersected with one of Sydney’s most serious domestic terror plots, offering a rare insight into national security, radicalisation, and the human cost of undercover work. Got any tips? Email us at [email protected]. Four Corners episode here: https://www.youtube.com/watch?v=pHnaHHC8Q9c  ASIO's statement in response to the ABC's Four Corners: https://www.asio.gov.au/asio-statement-four-corners  Credits:  Reporter/Host: Joey Watson Supervising Producer: Claudianna Blanco Fact Check: Holly Mitchell Sound Design: Matt Nikolic Head of Factual: Clair Weaver See omnystudio.com/listener for privacy information.