Fernando Meirelles set the film world alight with the stunning City of God, set in the slums of Rio de Janeiro. He's not turned his kinetic attention to Africa for a riveting adaptation of John Le Carre's The Constant Gardener. Donald Clarke meets a Brazilian director with energy to spare.

A FEW years back, everybody was babbling about the new wave of film directors from South and Central America - Alfonso Cuarón, Alejandro González Iñárritu, Walter Salles, Fernando Meirelles - who were attracting unusually large audiences for their films in Anglophone territories. Though we may not have said it explicitly, we probably reckoned that only one or two would follow up their first big hit with another international success. We were wrong. Films such as Iñárritu's 21 Grams, Salles's The Motorcycle Diaries and even Cuarón's Harry Potter and the Prisoner of Azkaban episode demonstrated these guys were around for the duration.

The most pressure was, arguably, on Meirelles. The Brazilian director's City of God, a frantically exciting drama set in Rio's vast slums, was a massive hit in 2003. In recent years only Crouching Tiger, Hidden Dragon has done such a good job of winning over those cinema-goers allergic to subtitles.

"And it was a blockbuster in Brazil," Meirelles says. "It got both the best reviews and the most negative reviews there. Some people were unhappy with the way it talked about the slums. Some people were saying: 'Oh, this is really too like an American film'. But I financed much of it myself. There are no sex scenes. There were no famous actors. So how was it part of any formula? Anyway, it was a success."

In the year following his triumph, Meirelles, who received an Oscar nomination for the film, found himself deluged with scripts.

"I wasn't actually offered X-Men 3," he laughs. "There were some bad scripts. There were a lot of good scripts. I was considering doing one about Hemingway with a major actor. I was also offered Collateral, which at that stage was going to be shot with Russell Crowe. I intended to do it more as a comedy, which the studio was quite interested in. But I eventually decided against it."

Instead, Meirelles elected to pursue an epic romance provisionally titled - note the tantalising allusion to a DW Griffiths epic - Intolerance. But, while taking a break from research, he was persuaded by producer Simon Channing-Williams to have a glance at Jeffrey Caine's adaptation of the John Le Carré novel, The Constant Gardener. Mike Newell had been attached to the project before he was lured away by the offer to direct the fourth film in a franchise focusing on some juvenile wizard or other.

"It was set in Kenya, where I had just been and where I was eager to shoot. So that was an amazing coincidence. It was about the drugs industry, which I was very interested in, and it was such an original love story."

Le Carré's book tells the story of a British diplomat's attempt to discover the circumstances behind the mysterious death of his wife, a dangerously inquisitive political activist. It transpires that she had uncovered a scheme by a pharmaceutical corporation to use poor Kenyans as guinea pigs for the testing of a new product. Foul play seems likely.

The most powerful player in the Gardener operation appears to have been Le Carré. Interestingly, despite the fact that nobody had made any serious money out of a film adaptation of one of his books since The Spy Who Came in From the Cold way back in 1965, the veteran author was consulted on every aspect of the production.

"In his contract he had final approval on the script and the director," Meirelles explains. "So I suppose he can't complain. He also had the right to approval of the final cut of the film. We had an official screening and he was very happy. But he was very helpful with any changes that we wanted to make. He is actually an incredibly nice guy. A very nice guy."

Le Carré chose wisely. Featuring the same striking use of colour and feel for location that made City of God so remarkable - Meirelles learned all the right lessons from his years as a commercials director - The Constant Gardener is a triumph. Ralph Fiennes and Rachel Weisz are excellent in the lead roles. The music is gorgeous. The editing is ingenious. But is the film maybe a little too beautiful? If one wished to play Devil's advocate, one might point out that the poverty of Nairobi's Kibera shantytowns (like that of the favelas in Meirelles's previous film) is shown in the most flattering shades.

"There is energy in these places and you feel that," he says. "I am always criticised for showing poverty with dancing and a degree of happiness. People like us from the rich parts of the world tend to want to see misery in these places. But when you go there that is not always how it is. The slums in Rio can be fun: people dance and listen to music. They often have a great time and when I went to Kibera it was the same. Of course, the conditions are hard, but if you ask the average 35-year-old guy about his problems he'll say, 'Oh, my girlfriend. My wife'. That's just like anywhere else."

So how would Meirelles, who was raised in a solidly middle-class area of São Paulo, compare the destitution in Kibera with that of the Rio slums?

"The big surprise was that it was even worse," he says solemnly. "There they didn't even have water. They would walk for hours to fill one bucket and then have to pay for it. But it was actually easier to shoot there than in Rio, because there is no drug traffic. It is not at all a violent place. We have these scenes where Rachel walks around Kibera and they were shot with just a crew of three people or so. We were six people walking round Kibera and it was perfectly safe."

Simon Channing-Williams, one of the producers of the Irish film Man About Dog, was committed to ensuring the production left a positive legacy. A bridge was constructed linking two distant areas of Kibera and money from the budget was directed towards developing fresh water supplies.

"We put in a shower and toilet block," Meirelles says. "It is important when somebody walks back from work that they can have a shower. And, yes, the money was from the budget. But, also, everybody in the crew donated money and Simon even persuaded Focus Films to donate some of the film's profits towards a charity he set up."

So, in the unlikely event you can't stand The Constant Gardener, it might be best to refrain from demanding your money back.