The 38th Toronto International Film Festival (TIFF) kicked off on Thursday (September 5) with The Fifth Estate, Bill Condon's big screen adaptation of the story behind anti-secrecy website Wikileaks and its founder Julian Assange.

Hundreds of fans cheered outside Roy Thomson Hall as they got a peak of cast members who arrived to walk the red carpet.

Actor Benedict Cumberbatch, who portrays Assange in the film and has roles in two other films in the festival, signed autographs before posing for photographers.

"It's an amazing moment," he said. "To be playing the lead role in the opening gala film of the 2013 Toronto Film Festival, it's really, really exciting."

The film is based on the book by Assange's once trusted lieutenant Daniel Domscheit-Berg about events that led to the largest leak of official secrets in American history in 2010.

Director Bill Condon said he set out to make a political film that would spark conversations, without telling audiences what to think.

"I think too often political movies tend to be narrowly ideological. They come in with a point of view and then just sort of make you want to feel that way. And this one I didn't even know exactly how I came down on everything because it is so complex. So what about just doing the other thing, which is just laying out all the sides of it, the complexity, letting the audience walk away with a very entertaining experience I hope, because it is a thriller, but also walk away with sort of information that allows them to have a conversation," Condon told Reuters Television.

As for his own feelings about Assange, Condon said "It remains completely complicated for me. There are huge aspects that I admire, some I'm not sure about so it's still a great big ball of gray."

Assange panned the film after reportedly seeing a copy of the script, and refused to co-operate with film makers. Now that it's finished, Condon thinks Assange may be surprised by what he sees on screen.

"As well as calling it an act of propaganda it's always described as the anti Wikileaks movie," Condon said. "I think anybody who sees this movie -- well, that's one thing -- it's a flat out celebration of Wikileaks and what they did. So I think yes, there are scenes that are critical of him but I think ultimately, I hope, a very, very balanced portrait. I think he might ultimately be surprised."

The Fifth Estate leads other films at this year's festival that deal with transparency including, The Armstrong Lie and Trap Street.

TIFF has come to be known as the starting block in the race for Oscars six months down the road. The coveted People's Choice Award propelled the fortunes of Slumdog Millionaire, and The King's Speech, which both went on to win the Academy Award for best picture.

World premieres of note in Toronto include August: Osage County starring Meryl Streep andJulia Roberts in a drama of a dysfunctional family, and Dallas Buyers Club, in which Matthew McConaughey plays an AIDS activist who smuggles treatment drugs from Mexico.

Presented by Adam Justice