BAREFOOT labourers, skinny housewives and half-naked, snuffling toddlers wait outside a corrugated-iron and plywood shack in a Delhi slum to see “the Bengali doctor”. Noor Muhammed, the nattily dressed 30-something inside, is indeed Bengali, but, as he cheerfully admits, not a doctor. Yet as he makes quick temperature and blood-pressure checks and hands out tablets—many of them antibiotics—his patients nod respectfully, and pay.

Last month the discovery that an unqualified “doctor”, Amit Kumar, had run a lucrative organ racket for nearly a decade caused a furore in India. Operating from Gurgaon, a booming Delhi satellite, Mr Kumar is accused of having paid or forced hundreds of poor people to provide wealthy clients with kidneys. Organ-trading has been illegal since 1994. But India has done little to curb its “quacks”, as medical impostors are known.

India has more fake than genuine doctors, according to K.K. Kohli, who chairs the anti-quackery committee of the Delhi Medical Council. In Delhi alone there are around 40,000. In the teeming slums where up to a third of the capital's population of 14m live, requests for directions to a doctor will lead to one of many dingy clinic-shacks, where a man who looks more prosperous than his neighbours plies his trade with a stethoscope, a thermometer and a big pile of pills.

“They take acute patients and make them chronic,” says Dr Kohli, citing quacks who misdiagnose, prescribe steroids as pick-me-ups, mix their own remedies and buy cheap, out-of-date antibiotics. Their most common error is prescribing and selling antibiotics unnecessarily. Sandeep Guleria, a professor at the All India Institute of Medical Sciences (AIIMS) in Delhi, says quacks have helped cause the high levels of drug resistance in India.

Ten years ago Delhi's state government drew up an “Anti-Quackery Bill” of which nothing more was heard. But the real problem is less the quacks themselves than the health-care vacuum in which they flourish. India's private health business is booming, importing flashy technology to serve a growing middle class and foreign “medical tourists”. But the public health system remains skeletal. There are only 60 doctors for every 100,000 people in India, compared with 257 per 100,000 in America. In slums, sick poor people go to quacks because government-run clinics are too far away and the queues too long. In many rural areas, there are no clinics.

Indeed, so essential are quacks to India's health-care system that the National AIDS Control Organisation says it is planning to include them in its AIDS-control programme, training them in basic care and counselling of people with sexually transmitted diseases. Some quacks, of course, may be perfectly responsible. Mr Noor, for example, swears that he refers all “serious cases” to government hospitals. How he diagnoses them is not clear.