Reports say an Indian doctor has come under fire over claims of treating incurable or terminal illnesses using embryonic stem cells without any safety trials and randomized clinical studies.
Delhi-based doc Dr. Geeta Shroff is charging as much as 30,000 pounds for a single course of treatment.
And medical researchers are deeply skeptical of her claims, and brand many rogue stem-cell physicians dangerous quacks offering expensive, unproven and potentially dangerous treatments that are banned in Britain.
However, some of Shroff's patients insist that they are getting better.
Shroff said that she has already treated 700 people, including several Britons, since 2002, by injecting them with embryonic stem cells capable of replicating themselves and of giving rise to almost any specialized cell type.
She claims that all the cells she uses are derived from a single unwanted embryo left over from an IVF treatment and the results, she says, have been remarkable.
"Almost all of my patients have shown improvement," Times Online quoted her as saying.
She claims there have been cases in which paraplegics have regained the use of limbs and of patients with Parkinson's disease and multiple sclerosis whose physical degeneration has been halted.
However, she said: "It's not a miracle, it's science. Theoretically, it can treat all of mankind."
Shroff has refused to publish her research and to submit it to peer review - a practice regarded widely as a cornerstone of good science.
Instead, she has patented her technique, a route more familiar in business than medicine.
Doctors say that without safety trials and randomized clinical studies, her treatments are unverifiable and potentially dangerous.
And there has been no research published, for instance, to rule out placebo effects.
"If somebody spends thousands of pounds, it's pretty hard to convince them it's not money well spent," said Anthony Mathur, a cardiologist at the London Chest Hospital working on stem-cell research.
"If her claims are true, they will revolutionize medicine. I find them hard to believe, but am prepared to keep an open mind. What is harder to explain is why so little important information about them is being shared with the medical community. It's wrong to give out hope and no facts," he added.