Sorious Samura is not a man who believes in making life easy for himself. For his latest film, Living with Illegals, the award-winning documentary-maker joined a group of economic migrants and smuggled himself from Morocco into Spain and then across France and into England, hiding inside a cross-Channel lorry.
In an attempt to fully experience the reality of being an illegal immigrant, he subjected himself to the same hardships as his companions - living in a cold tent in North Africa as he watched for the moment to "strike" into Europe, sleeping on the streets of Barcelona, begging for food, scamming to raise the cash to pay the smuggling mafia, fare-dodging on trains, and sleeping rough in Calais during repeated attempts to get across the Channel undetected.
It's not the first time Samura has put himself through this kind of ordeal. The man Time magazine put on its list of 30 people "who had made an outstanding contribution to world affairs" a couple of years back, has made something of a speciality of putting himself into gruelling situations.
What brought him to international attention was an ordeal that was thrust upon him. When, in 1999, rebel troops invaded Freetown, his home in Sierra Leone, Sorious Samura was the only person on the spot with a video camera. (He worked in a theatre and used it to make films of traditional dances to sell to tourists.) With extraordinary bravery he ventured out on to the streets to film, and continued to do so even after being captured and threatened with death.
His footage won him the Roy Peck Prize for freelance cameramen, and it was seen across the world, thanks to the BBC and CNN - after the main US networks refused to show it because it was too graphic.
"Which was ironic," Samura says now, sitting in the safety of his south London production office, "considering the amount of Hollywood violence they're eager to screen and how they go on about the freedom of the press." Eventually he made his own film from the footage, Cry Freetown, a chilling portrait of man's inhumanity to man.
After which, you may think, he might have looked for some less challenging subjects. But he has embarked on a series for Channel 4 called Living with..., which sets out to put Samura inside grim situations that the rest of the media view only externally. "Journalists always go away at night," he says. "I want to show what happens when they're not there."
There is, in the event, a bit more to it than that. For the first of the series, Living with Hunger, he went back to basics at the time of the Live8 concerts, moving into an Ethiopian village and eating only what the villagers ate, and drinking what they drank, for a month.
In Living with Aids, he worked as an orderly in a hospital in Zambia. And in Living with Refugees, he travelled with a family fleeing the genocide in Darfur on their grim trek to a refugee camp in Chad. The films were simple, but offered a profound insight into what life is really like for the poorest people in the world.
In Monday's Dispatches slot - which he wanted to call "I'm an African, Get Me Out Of Here" - Samura tackles the thorny issue of economic migrants. "I don't like to use the phrase 'illegal immigrants', unless you also want to apply it to the Europeans who colonised Africa," he says.
The facts in the programme will surprise no one. Thousands of Africans looking for a better life are smuggling themselves into Europe each year - and many are dying in the attempt, as the bodies washed up on the coasts of Spain and Italy testify.
What is striking is the detail Samura turns up on the journey: the migrants' perilous attempts to swim to their promised land; the cat-and-mouse games they play with the police around Ceuta, the Spanish enclave in Africa; the years it all takes, selling roses or batteries in tourist spots to raise the cash to pay the smugglers to get them across each border, which costs between €500 (£350) and €800 per frontier; and the exploitation they suffer at the hands of the people-smugglers.
"What you meet are real people, not stereotypes," he says, "and they are courageous, patient, tenacious, ironic, emotional." They are, above all, individuals rather than stereotypes of undesirables, though the experience of the journey makes them feel like that. "We are like animals," one says. "Like dogs," says another. "Worse than shit, if I may say so," says another, with pathetic politesse.
It is the detail that is most affecting. In the hunger film, the starving Ethiopians react hysterically when they first meet the big fat Sierra Leonean - they assume he is a cannibal, or even the Devil, for Ethiopian Orthodox Christianity depicts the Devil as a very black being. In the refugees film, there is a chilling moment when a woman stands on the edge of the desert and in a deranged manner berates her menfolk for being cowards. In Monday's illegals film, there is an extraordinary generosity among the destitute migrants who, time after time, share what little they have with one another.
There are those who have cast doubt on the ethics of the approach. The Channel 4 News cameraman Tim Lambon, who has worked with Samura, has publicly criticised his colleague for resorting to a form of reality TV. Taking a 16.5-stone adult man who was "a total stranger to hunger" and planting him in a village of starving people was, Lambon said, just a gimmick. Healthy black African males are not the people under threat: "The people under threat are the elderly and the young. Better to have taken Sorious's children and let them starve for a month and see him watching them. That would have been reality." By the end of the month Samura had lost three stone and he returned to the plenty of London. But for the people of Ethiopia, there was no ticket out.
Samura is unapologetic. "Had we just gone and interviewed the villagers, broadcasters wouldn't have had the confidence that the audience would watch. Coverage of Third World issues has always brought little viewership. By being there I was letting the villagers tell their own story, but I was mediating it to a white audience in a way that Alamnu [the mother of the family he stayed with] couldn't have done.
"The film wasn't about Sorious Samura starving in Africa. It was about me trying to understand these people's experience and through that experience to tell their story better - but letting them represent themselves, and tell their own story."
The hard truth is, he adds, that if he had not been there, no film-maker would have left video equipment with the Alamnu family. "I've been given a chance to stand up and use my voice for the innocent, the defenceless, the voiceless," he says.
Samura is unafraid to ask hard questions. In the Aids film, he meets two men, Joshua and Lawson, who are still having unprotected sex even though they know they are HIV-positive. Like so many African men, they think that anything less than "skin on skin" sex is not proper, a cultural attitude that is rooted far deeper than religious attitudes about abstinence.
Samura lambasts them for their irresponsibility. Disease and fatalism have combined to break down the family structure entirely in many parts of Africa, he concludes.
And in the illegals film, he lays in to the African smugglers who con their fellows out of the little they have. "You are the sort of people who are corrupting Africa. You are wicked, you are the kind of people who are destroying the continent," he screams at them.
"Most ordinary Africans would love to be able to ask the questions I'm asking," he says. "I owe it to ordinary Africans to ask the uncomfortable questions."
Yet he has no hard policy questions to ask of British immigration procedure. His concerns are not to do with politics, so much as to expose how deeply into human lives easy policies can cut. After living with the migrants, he turns to the camera at one point and says simply: "I'm beginning to understand why people risk their lives to get out of this mess."
In part, his sympathy comes from his own background. He was born into a very poor family of the minority Limba tribe. His family of eight lived in one room, and he did not own a pair of shoes until he got to secondary school. When he came to London in 1994, for the first two-and-a-half years he worked round the clock, cleaning Tube trains all night, working at Burger King all day and at Blockbuster video in the evenings. He slept only on the Tube between jobs and on Sundays.
"I have experienced the lives of the unseen people who clean our offices and hospitals and buses at night, who do the job that born-British people won't do but who mostly come from our former colonies and feel that they'll have a better chance of survival here.
"I understand them. They are my people. Are they really white Europe's worst nightmare?" he concludes. He does not need to pause for an answer.
'Living with Illegals' is on Channel 4 at 8pm on Monday