South Korean cloning pioneer responds to accusations

South Korean cloning pioneer Hwang Woo-suk has defended himself in the media following allegations over ethics violations that have seen his groundbreaking work plunged into controversy.

Hwang Woo-suk says that he tried to talk junior scientists at his lab out of donating their own eggs for research, however, he admits he did not check to confirm they had not in fact donated their eggs later.

Documents obtained from Hwang's lab show that possibly six hundred human eggs had been bought for Hwang's research.

Although the egg buying would not have been illegal at the time, Hwang has always insisted all eggs he used were given by donors enthusiastic to see his work proceed.

Hwang has received worldwide acclaim for his breakthroughs in cloning the world's first human embryos and extracting stem cells from them.

However the recent controversy surrounding Hwang has prompted some of his collaborators, including University of Pittsburgh researcher Gerald Schatten, to quit an ambitious international cloning project announced last month that aims to find treatments for incurable diseases.

Hwang vehemently denies all the allegations, and says all the eggs he used for his research were donated voluntarily in line with government guidelines.

Chairman of the board at Mizmedi Hospital, Roh Sung-il, has however revealed that he paid 1.5 million won ($1,400) each to some 20 women in late 2002 to obtain their eggs for research, which contradicts his earlier remarks that none of the bought eggs were used for research.

Roh says that Hwang had not known about the payments that came out of his own pocket.

Although the payments were not illegal at the time, in January, South Korea enacted a law banning commercial trading of human eggs.

Collecting human eggs is crucial for embryonic stem cell research, which involves cloning embryos to extract stem cells, the master cells that can grow into all kinds of tissues in the body and are seen as a potential source of replacement tissue for people with a variety of ailments.

In order to do that, a human embryo must first be cloned from a patient's DNA, which is inserted into an unfertilized egg to produce the embryo.

Obtaining eggs is a problem for researchers, especially considering how inefficient cloning technology currently is.

South Korean researchers in 2004 used 242 eggs from 16 donors to yield just one cloned embryo, which was destroyed after several days to extract stem cells.

Despite the controversy, South Koreans' support for Hwang remains strong.

A private foundation was launched this week to promote egg donations and more than 100 members of Hwang's Internet fan club have volunteered to donate their eggs.