In the 1970s, Christopher Boyce's name became inextricably linked with the political tensions of the time when he was jailed for selling classified US information to the KGB in the Soviet Union.
The spy's story was also made famous by the movie, The Falcon and The Snowman, but in recent decades Boyce has been off the radar.
Mark Davis tracks him down to the mountains of Oregon, where he's been living in virtual anonymity since his release from prison.
In an explosive interview, Boyce recounts his time working for a CIA subsidiary that provided satellite equipment to the spy base at Pine Gap in central Australia.
And he makes claims that during the time of Gough Whitlam's troubled government, the CIA was interfering in Australian politics and its trade unions.
The story, first screened in February 2014, was shown again on the Best of Dateline in February 2015.