Gianfranco Rosi, a talkative Italian with a broad face and a warm laugh, is one of the few film directors to have picked up both a Golden Lion and a Golden Bear. The awards for best film at, respectively, the Venice and Berlin Film Festivals are the only such gongs that compare with a Palme d’Or. This makes him a sort of cinematic Count. Right?

“All that means is that I have to forget everything,” he says. “I have to start from scratch. Every film is my first film and last film. I always start again.”

Rosi is a documentarian. The strange, evocative Sacro GRA, which won Venice in 2013, tells stories from the motorway that orbits Rome. His latest film, Fire at Sea, which triumphed at Berlin a few months ago, studies the island of Lampedusa during the recent immigrant crisis. Tucked between Sicily and Tunisia, Lampedusa has been a stepping-stone between continents for centuries.

“It’s the last post of Europe. For 20 years, Lampedusa has been approached by refugees from Africa. It seems only last summer people noticed. ‘Oops! People are arriving.’ In the past 15 years, 100,000 people arrived there and then spread around Europe. It all changed when there was a terrible accident. It got militarised then. People ask me why there is no interaction between people and the migrants in the film. I say: ‘Because there is none. They are kept apart as the migrants are moved through’.”

As Rosi suggests here, Fire at Sea is not quite what you might expect from any one-line synopsis. This is not a noisy exercise in handheld verité. The shots are long, carefully composed and often rather beautiful. Though he encounters tragedy on the seas and hears harrowing stories from immigrants, most of the film's focus is on residents of Lampedusa. He follows one boy as he makes a catapult from scratch and plays war games among the cacti. We meet the doctor whose very ordinary practice is regularly interrupted by his work at the holding centre.

“The language and structure of cinema has always been important to me,” he says. “I work on my own and that allows me a lot of time to wait for the right moment. It’s about transforming reality. I hate it when people say ‘the camera becomes invisible’. That never happens.”

Not the nine o’clock news

Gianfranco must surely expect that his film will be presented as a documentary on “the refugee crisis”. The story is now so huge that it is unavoidable. People will expect to see a narrative ripped from the headlines. The film is, however, something very different. Have audiences been disappointed that it does not engage more directly with the political issues?

“Absolutely. To be honest the film is political beyond my intentions. Outside the frame politics are pushing their way in. Those stories are pressing themselves on to the characters from the outside. There was no way that wasn’t going to happen. But if the film had been released two years ago people would have seen things very differently.”

A brief glance at Gianfranco's biography suggests obvious motivation for embarking on Fire at Sea. He was born 42 years ago in Eritrea and lived there until he was 13. He later lived in Rome and Istanbul, before enrolling in NYU Film School (hence his perfect English). Eritrea is one of the countries caught up in the current crisis. There must surely have been some compulsion to work through lifelong anxieties and interests.

“No. Maybe unconsciously,” he says. “Look, it’s a problem that all Europeans should concern themselves with. There are people coming from Eritrea, from Ivory Coast, from Sudan. One million from here. A hundred thousand from there. There are biblical movements.”

Unstoppable force

He laughs caustically.

“And the good news is that nobody can stop them. You appreciate my irony. We have to stop using the word ‘emergency’. It’s not going away.”

In pointing out Rosi’s oblique approach to the material, we should clarify that he includes striking and often harrowing shots of arriving migrants. The rustle of gold foil blankets in the moonlight becomes a repeated visual refrain. After spending 40 days in a military boat, he encountered a vessel laden with dead and dying migrants. Here is where the documentarian faces the greatest moral challenges.

“I encountered a big tragedy. I encountered death,” he says. “I had to decide whether to film or not. I decided I had to. The world needs to see tragedy with a human face. It is unacceptable that people die escaping from disaster. Europe will at some point have to take a position on this.