In a stinking, smoking room in which large metal cauldrons spat and sizzled atop wood-fuelled fires, Dr Nandini Bhojraj pointed with pride to four plastic buckets placed on the floor. One, she declared, contained cow's milk, another cow's urine, a third "dung juice" created by soaking cow excrement in water, while into the last had been poured clarified butter, or ghee.

The purpose of the witches' kitchen-like set-up was to heat and combine all four to create a wonder drug for humans. "It will cure 99 per cent of all diseases," Dr Bhojraj declared. For more than a decade, she and a team of fellow enthusiasts and activists at the Go-vigyan Kendra institute and farm in central India have been quietly researching the medicinal and health-boosting qualities of the Indian cow.

Using principles they say come from both ancient medicine or ayurveda and Hindu texts, they have created a range of items based on cowpathy, or the five traditional cow products – milk, urine, dung, butter and ghee.

There is shampoo to prevent dandruff, mosquito repellent, incense, tooth-whitening powder manufactured from dung charcoal as well as the more obvious fertiliser and insecticide. At one point, a sister farm in the north of India even had plans to produce a soft drink from cow's urine. But earlier this summer, the establishment of 280 cows and 50 staff set amid the thick jungle that is home to groups of langur monkeys, captured the headlines when it announced it had obtained patents in the US and China for another distilled urine product, marketed as Gomutra Ark, that it claimed could help cure cancer and several other serious conditions.

While, by itself, obtaining a patent is no proof of anything, its boasts were supported by the government-funded National Environmental Engineering Research Institute (NEERI). At a press conference one of its senior officials told reporters: "Many patients, some of them terminally ill with diseases like cancer, have come to the Go-vigyan Kendra for treatment and have claimed to have benefited from Gomutra Ark." The institute responsible for producing this drug is located about 40 miles east of Nagpur, a city of 2.5m people that sits at the geographic centre of India.

In addition to the cowsheds where workers from nearby villages gather dung and urine, there are several rather scruffy buildings that serve as laboratories, workshops and offices. There is also a hostel for children who attend a local school. The establishment was set up 15 years ago with money and support from a controversial Hindu nationalist organisation, the Vishwa Hindu Parishad (VHP), but officials say the centre is independent because it is now funded solely by the sale of its products and donations.

Yet its aims – research into the five cow products ("panchagavya" in Sanskrit) and the promotion of the cow as being central to human existence – remain the same. "We initially came to look at the Indian lifestyle with the focus on the village and the cow. It all depends on cows. We want to look at how we can help put the cow at the centre," explained Suresh Dawle, the institute's secretary. "India's system depends on the village and the village depends on the cow – to fertilise the land, for milk, urine for pesticide. If the cow is at the centre then the economy will grow." Asked if the institute was also proselytising Hindu beliefs, he demurred: "Hinduism is a way of life. It's not religion, it's a way of life for mankind. This is not related to religion."

Yet a stroll around the grounds of Go-vigyan Kendra left little doubt about the way in which the cow is venerated here. A noticeboard listing daily activities mentioned that 9am was time for "cow worship", when the animals are washed, scrubbed and a prayer ritual, which involves encircling the cow with incense and painting a red dot or tika on its head, is performed.

The cow has long been at the centre of often vicious political and cultural battles in India. Considered sacred by Hindus and protected by law, purported attacks on cows are often used as rallying device by right-wing Hindu groups, such as the VHP. Dalits, or so-called untouchables, are often attacked, beaten and even murdered after being accused of killing or eating cows, something that is banned in the majority of Indian states. Just last week there were protests from Dalits and others in the southern state of Karnataka where the state government passed new legislation to ban eating cows or buffalo. Yet despite their supposed high status, cows often live a shabby life in India, especially in large cities where they idly wander the traffic-choked roads or graze on piles of festering rubbish and plastic bags. In Delhi, the government employs teams of urban cowboys to catch the stray animals and take them away on trucks to farms on the city's edge.

Asked to explain this apparent discrepancy, Mr Dawle said: "Britain ruled India for 200 years, broke the village economy and imposed their lifestyle on Indian people. People forgot the importance of the cow." If people at the institute have their way that will never happen again. Dr Bhojraj said in addition to the Gomutra Ark, 28 products manufactured at the institute had received clearance from the government's food and drug safety body. Best of all, she said, there were no side effects from these products, not even from the fearsome-sounding concoction that her staff had been making in smoking pans.

Her words were still ringing out a few moments later when it was time to test the raw materials the wonder drugs are made from. In a small room at the rear of the institute, several clay pots were lined up against the wall. Dr Bhojraj lifted the lid from one of them and scooped out the light, straw-coloured liquid with a small metal cup.

"It is eight-day-old distillate of cow's urine," she said. "It may smell quite strong." Indeed it did. But the smell of this aged urine, however bad, was nothing compared to its taste. Just the smallest sip was enough to trigger a flurry of different associations – burning grass, petrol, Laphroaig whisky, rancid sourness – that produced a vile gustatory overload. The heart seemed to beat faster, the brow sweated. Would it be deemed impolite to step outside and spit? "Perhaps you'd like some water," enquired Dr Bhojraj. One might assume something that tasted so bad must do some good.

In the US patent for Gomutra Ark, the product was described as a "composition useful for protecting and/or repairing DNA from oxidative damages". Dr Bhojraj said chemicals in urine caused cancer to cells to "commit suicide". And it is not just cancer. One of the institute's books claims Indian cow's urine – and it must be Indian cows, they insist – can also help treat renal failure, leprosy, skin disease, piles, anaemia, jaundice, mouth ulcers and ear disease.

In India, drinking urine has a long history and may stretch back thousands of years. One ancient text, the Damar Tantra, is said to contain more than 100 verses on the benefits of both drinking urine and of massaging it into the skin.

The late Indian prime minister, Morarji Desai, who served between 1977 and 1979, was famous for his championing of so-called "urine therapy" and claimed drinking his own had helped him get rid of piles. He even once told an interviewer that drinking urine could be a "perfect" medical solution to millions of Indians unable to afford doctors.

Yet for all its champions, most experts, at least outside of India, have concluded there are no benefits to be obtained from drinking it.

Dr Donald Hensrud, chairman of preventive medicine at Mayo Clinic in Minnesota, told ABC News: "I think I'm perfectly comfortable in saying that I'm aware of no data that cow's urine – or any other species' urine – holds any promise... in treating or preventing cancer." Such opinions will do nothing to deter the friendly and charming people at the Go-vigyan Kendra.

When it was time to leave, The Independent was escorted from the farm by Madhu Rotkar, a former civil servant who worked there as a volunteer. He was 76 and yet appeared to have boundless energy. Asked, inevitably, if he drank the purportedly-magical cow's urine, he replied with a smile: "Every morning."