Cloning expert tells of his shame at ethical lapses

Professor Hwang Woo-suk, a South Korean scientist, admitted two female scientists in his lab donated their own eggs for research - considered an unethical move because of the potential for exploitation - in a setback for the work that has raised worldwide hopes of cures for untreatable diseases using stem cells.

He announced he would resign as head of the World Stem Cell Hub, which was launched only last month in Seoul along with international researchers - "to atone to the public".

"I am very sorry I have to tell the public words that are too shameful and horrible," Prof Hwang said.

"I should be here reporting the successful results of our research, but I'm sorry instead to have to apologise."

The foundation had announced plans to open cloning centres in San Francisco and London, but Prof Hwang's United States collaborators, including University of Pittsburgh researcher Gerald Schatten, have dropped out of the project following allegations of unethical egg collection.

Prof Hwang is a national hero and has gained international renown for his breakthroughs, including cloning the world's first human embryos and extracting stem cells from them. Earlier this year, he unveiled the world's first cloned dog.

Prof Hwang, who was feted by scientists when he visited Scotland this year, said he would continue his research at Seoul National University.

The Korean health ministry said earlier yesterday that an ethics investigation at the university found the two junior scientists gave their own eggs for research.

However, the donations were not in violation of ethics guidelines because they were made voluntarily.

The allegations were first made last year in the journal Nature. Prof Hwang said a reporter had asked him about a scientist's eggs in May 2004, the first time it was brought to his attention.

He asked the scientist about it and she admitted it, but Prof Hwang said he publicly denied the report because she asked that her privacy be maintained.

However, he added: "The responsibility for all disputes and controversy lies on me. I will not make any excuse.

"I have learned a painful lesson that I should conduct research in a calm and cautious manner by living up to a global standard."

The health ministry also confirmed that a doctor who had earlier been collecting eggs for the research paid some women for their eggs.

Prof Hwang said he had asked the doctor about the source of the eggs and was told not to worry. Payments to egg donors were not then illegal and ended in 2003.

Professor Ian Wilmut, the Edinburgh University scientist behind the world's first cloned mammal, Dolly the sheep, and Professor Christopher Shaw, of King's College London, issued a joint statement: "We are saddened by the confusion that has arisen in Korea and the distress that has been caused to those concerned.

"In the UK we are fortunate to have had the Human Fertilisation and Embryology Authority in place for 15 years to supervise all research with human embryos."

Professor Peter Braude, also of King's College, said: "This is an awful shame.

However, it does not detract from the very real advance the group has made. The means to achieving this is questionable, not the data. We must give serious thought to how we can obtain eggs from young women in an ethical way."