TORONTO -- When Alex Gibney decided to go ahead with a documentary on Lance Armstrong's fall from grace, there was a personal element to his storytelling.

The Oscar-winning director had originally shot interviews and footage of the now discredited cycling champion while Armstrong plotted his comeback to the sport in 2009, a project which was shelved as the seven-time Tour De France winner came under increased scrutiny from authorities.

But after a barrage of doping allegations, increasingly hard-to-ignore evidence and an eventual admission from the athlete himself captivated international spectators, Gibney decided to make a different kind of documentary -- aptly titled "The Armstrong Lie"

-- which juxtaposed past denials from Armstrong with his later admissions of guilt.

The extraordinary access Gibney had to the cyclist also meant, however, that the director himself had been repeatedly lied to by Armstrong.

"I felt like I was being made to be part of a con," said Gibney on Sunday while promoting the documentary at the Toronto International Film Festival.

"The idea that I was being played, that's what made me angry. That I was playing a part in burnishing Lance's reputation."

While unhappy about being deceived, Gibney turned his own experience with Armstrong to his advantage, using it to drive his search for answers from the athlete who famously beat cancer and at one point had come to represent pure human resilience against the odds.

"You don't want that anger to blind you," Gibney explained. "Ultimately part of what I had to investigate was my own role, not only as a filmmaker but also as a fan. Because then you understand the story a little bit better."

After more than a decade of denials, Armstrong told Oprah Winfrey in a January interview that he used performance-enhancing drugs to win the Tour de France seven times, titles that have now been stripped away. He has been banned from cycling for life.

Gibney's documentary features clips of that much-watched interview, captures Armstrong on camera right after he spoke with Winfrey and questions him at a later date as well.

In discussing his film, Gibney admits he wasn't as suspicious of Armstrong as he could have been, but said his own approach to the cyclist mirrored that of many others.

"I think one reason that the lie got so big is that Lance saw how much people liked the lie and it was a magnificent lie," he said.

"I think some part of Lance was just saying, 'Look, I'm just giving people what they want."'

"The Armstrong Lie" will be released in select theatres Nov. 8.