'Blow' to stem cell research.
Revelations of fraudulent research have delivered a "major blow" to the progress of work on therapeutic cloning and stem cells, a leading British scientist said yesterday.
South Korean researcher Dr Woo Suk Hwang faked all of his landmark results, his university said.
The veterinarian had previously been idolised as the world's foremost stem cell pioneer.
But yesterday an investigating panel at Seoul National University said there was no proof he had ever produced stem cells from cloned human embryos.
The panel found that Dr Hwang did create the world's first cloned dog, an Afghan called Snuppy.
Dr Hwang had already been found guilty of fraud over his greatest achievement, generating embryonic stem cells tailored to specific patients.
None of the 11 stem cell lines matched the patients, as had been reported. Data was manipulated to make it look as if they matched.
After the verdict, Dr Hwang resigned and gave up his professorship.
Alison Murdoch, professor of Reproductive Medicine at the University of Newcastle, said: "It is regrettable that Professor Hwang's recent work has been called into question and it is a major blow that human therapeutic cloning now looks to be much more of a challenge than his recent reports led us to believe."
Last year Professor Murdoch's team produced Britain's first cloned human embryo, but failed to extract any stem cells from it.
Embryonic stem cells are capable of developing into any tissue in the body. Scientists hope that one day they will used to treat a host of diseases.
Dr Hwang claimed to have grown human embryonic stem cells and to have produced cultures which genetically matched the patients they were cloned from.
Scientists hailed the "breakthrough" as a major advance, heralding replacement tissue transplants which would not be rejected by the immune system.
Professor Murdoch said her team continued to have faith in therapeutic cloning.
"We are committed to continuing our research in this area as part of a broad portfolio of research into stem cell therapeutics," she said.
Professor Malcolm Alison, from the Institute of Cell and Molecular Science at Queen Mary, University of London, said he was astonished by the revelations.
He added: "DNA analysis these days is so routine that this fraud ranks almost as a schoolboy prank."
It was much less sophisticated than the Piltdown Man hoax of 1912, in which scientists claimed to have found the "missing link" between humans and apes, he said.
Professor Anne McLaren, from Cambridge University's Gurdon Institute, remained optimistic. She said: "The impact on South Korean science will be very much greater than any impact on stem cell research worldwide and future therapy."
Dr Stephen Minger, from King's College London, said: "All of us who admired Hwang are deeply saddened by this revelation. However, it is likely to have a minimal effect on stem cell biology per se and work in the field will continue."
Dr David King, director of Human Genetics Alert, which opposes therapeutic cloning, said: "So-called therapeutic cloning is a technological fantasy and it is high time the scientific establishment came clean and admitted the fact."
Hwang Woo-suk with Snuppy, the dog he cloned