In a startling insight into the champion swimmer's state of mind during this year's failed comeback bid, the film - to screen on ABC1 next Sunday - reveals Thorpe's dark days when, in 2010, he confirmed his financial empire was in ruins.
"I was down," Thorpe says of the period in which it was revealed his various financial interests - Thorpedo sports drinks and tuna steaks, and own-brand underwear and toiletries - were foundering. "I call it the dark times."
In the film, Thorpe is asked if he sleeps with men or women. He pauses before answering: "Ah, women."
The 29-year-old then details how, as a teenager, he discovered his strong appeal among the gay community.
"Being asked about (being gay) gets annoying," he says. "I think people feel threatened by me because they can't define exactly what I am."
Following the realisation he had not secured a place on the London team, a clearly dejected Thorpe says: "It's tough to comprehend. I worked so hard to do this, I haven't really thought about what to do now."