‘I live in a remote area of the Masurian forest in Poland and one night I was driving back home on a very slippery road. My car skidded and I very nearly went over the edge, which would have killed me. I felt a real shock and I realised I was near this secret military airport, where CIA planes land with prisoners they have taken in the Middle East.

‘I wondered what would happen if a vehicle in a military convoy carrying prisoners lost control on this road.

‘I had my story for the film. It would be about a man in chains, who runs away barefoot through the snow into the wild forest. I would leave the question of whether he is guilty or innocent open and ambiguous. The political aspects of the situation didn’t interest me: to me politics is a dirty game and I don’t want to voice my opinions. What is important is that the man who runs away is returning to the state of a wild animal, who has to kill in order to survive. Within two hours I sketched an outline, and it took ten days for my wife Eva [Piaskowska] and myself to finish the script.

‘I’ve known Vincent Gallo socially for several years, since we acted on a film together, LA Without a Map. There’s an animalistic quality to his movements, which I thought would be perfect for the role of the fugitive, who doesn’t speak. I gave him the script at Cannes in 2009, and within 24 hours he called to say that he had to do it. He insisted he could cope with the cold, because he’d grown up in Buffalo, New York.

‘I had wanted to film Essential Killing in the area around my house, like I had for my last film Four Nights with Anna. I like sleeping in my own bed and not having to travel hours to locations. But we couldn’t guarantee snow in Poland, so we ended up shooting in Norway.’

Essential Killing, GFT, Glasgow from Friday 1–Saturday 9 April; Filmhouse, Edinburgh from Friday 29 April–Thursday 5 May.

Essential Killing Trailer