Entering Dharavi via a narrow path, I found myself in a large complex of two- and three-storey workshops where young workers were recycling plastic rubbish. They were separating it by colour and quality, cleaning it, chopping it up and eventually melting it, all by hand. I climbed up to a rooftop spread with white plastic chips. The uneven roofs of the slum stretched out for what looked like miles, broken only by the minarets of mosques.

Further inside the slum, walking carefully along pathways less than two feet wide, I came to a small cavern with a furnace in the middle. Teenage boys were taking thin, tinsel-like aluminium strips from piles of sacks and turning them into ingots. The fumes were overpowering but the boys, their dark hair glittering with tiny specks of aluminium, wore no masks. Moving on, I came to a small open area with a tea shop, and then an alley that led on to a wider path and eventually to a road wide enough for a car. The people in this corner of the slum were Muslim: many of the men wore beards and white hats and there were women wearing full black burqas. While Muslims make up 17 per cent of the population of Mumbai, they probably account for 35 per cent of Dharavi's.

Since Slumdog Millionaire, the Mumbai press has rediscovered Dharavi, because the book on which it is based is set there (Boyle filmed in several slums around the city to create one that stands for them all). "Until the '80s, we used to write a lot about these things," says Kalpana Sharma, former Mumbai bureau chief of The Hindu and author of Rediscovering Dharavi. Then they simply dropped off the media's radar.