A £10,000 challenge set up by a city professor has angered homeopaths.
Edzard Ernst, who researches complementary medicine at Exeter University, is offering a cash prize to anyone who can prove that homeopathy can be successful.Prof Ernst says the £10,000 reward will go the first person who can prove that the treatment works better than a placebo in scientific trials.
The professor claims to have carried out 200 strictly-controlled trials and says he is yet to find any firm evidence of successful homeopathy.
That is the belief that an ill person can be treated using a substance that can produce, in a healthy person, symptoms similar to those of the illness; for example, that the essence of an onion could be used to treat hayfever.
He said: "If you do a systematic look at all the evidence, you fail to demonstrate strong evidence in favour of homeopathy."
It is not the first time Prof Ernst has been critical of homeopathy. In April, he hit out at guides published by The Prince's Foundation for Integrated Health (FIH), saying they contained misleading and inaccurate claims about the benefits of alternative medicine.
He called for both Complementary Health Care: A Guide for Patients and the Smallwood Report to be withdrawn.
He said: "My job is to assess what works and what doesn't.
"I've done that for 15 years and have published thousands of papers which amount to considerable evidence.
"I think it's wrong that the public is being misled by a report from the FIH which is being paid for by taxpayers.
"I'm in favour of complementary and alternative medicine but it's got to be evidence-based. It's got to work and it's got to be safe.
"The almost indiscriminate approval from the FIH is almost dangerously misleading."
Homeopaths have reacted with anger to his £10,000 challenge, branding it a publicity stunt and they already had "more than enough proof".
Dr Robert Mathie, of the British Homeopathic Association, said: "What is needed is more investment in homeopathy research, not facile enticements by scientists who should know better."
Frederiek Maddock, a homeopath from Crediton, said: "Dr Ernst does not appear to have done his research properly and is very selective in what he decides to believe.
"This is not a very professional way to do this. Whether anyone will take up his challenge is a matter for the homeopathic association."
-- Richard Birch, with one of the announcements I've waited three years for, care of This Is Exeter.