Woo-Suk Hwang. Picture / Reuters

Woo-Suk Hwang. Picture / Reuters

The scientist who cloned the world's first human embryo yesterday resigned in disgrace from an international body after admitting that he lied about the source of the eggs used in his experiments.

Professor Woo-Suk Hwang of Seoul National University in South Korea apologised for repeatedly denying that some of the eggs had come from junior members of his own research team.

He said he was sorry for making misleading statements when questioned about whether the eggs had been procured unethically from young female colleagues.

Announcing he was stepping down as head of the World Stem Cell Hub "to atone to the public", Professor Hwang appeared downcast and solemn at a press conference yesterday.

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

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

Professor Hwang had been feted around the world when in February 2004 he announced that his team has cloned the first human embryo with a view to developing a new source of stem cells.

However, rumours later emerged that some of the eggs from the 16 volunteer donors came from his colleagues which, although not illegal, is considered unethical because the women have felt under pressure to cooperate.

Professor Hwang also said that no money had changed hands with the donors but it emerged this week that a colleague had in fact paid the equivalent of about £1,000 each to some of the women.

"Being too focused on scientific development, I may not have seen all the ethical issues related to my research," Professor Hwang said.

"At the time, technology was not as advanced as today and creating one stem cell line required oocytes [eggs].

"It was during this time when my researchers suggested making voluntary donations. I clearly turned it down," he said.

But it has now been confirmed that at least two women from his team did donate their eggs, a fact that Professor Hwang claimed he had only become aware of earlier this year.

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

"It is my way of seeking repentance. I again sincerely apologise for having stirred concern at home and abroad."