A Second World War codebreaker drama starring Benedict Cumberbatch has won the top prize at the Toronto International Film Festival.

Director Morten Tyldum's The Imitation Game claimed the coveted Grolsch People's Choice Award.

Cumberbatch plays British codebreaker Alan Turing.

The role is complicated because Cumberbatch not only must convey the mathematical brilliance of Turing, but the pressure he faced as a closeted gay man at a time when homosexuality was criminalised.

The film also stars Oscar nominee Keira Knightley and Matthew Goode.

Three of the past six People's Choice Award winners have gone on to win the Oscar for best picture, including The King's Speech, Slumdog Millionaire and last year's victor, 12 Years A Slave.