SEOUL: South Korean scientist Hwang Woo-suk and his team apparently achieved a world first by cloning human embryos even though parts of his later research data were faked, news reports said yesterday.

It remains unclear, however, whether Hwang's team went on to produce patient-specific stem cells as claimed, Yonhap news agency and YTN TV said, quoting an unidentified official with Hwang's Seoul National University.

In order to verify Hwang's apparently landmark 2005 paper published in the US journal Science, investigators from the university thawed and analyzed five samples of cells which were purportedly capable of developing into patient-specific stem cells.

However, the cells were frozen at too early a stage in their development to reach any conclusion, the reports said.

Stem cells are the body's master cells which experts believe can grow into any organ and thus someday can be used to help fight cancer and other diseases such as Alzheimer's, Parkinson's and diabetes.

Patient-specific cells would reduce the risk of rejection.

A university spokesman declined to comment on any new findings by its investigation, pending a final announcement expected sometime next month.

The investigators reportedly found the DNA of the five cell samples matches those of patients, which means that those cell lines were indeed obtained from cloned human embryos.

"The DNAs were matched but the samples are at an early stage of development. They can hardly be regarded as stem cells yet," the source was quoted as saying.

Experts here said that thanks mainly to the large number of human eggs Hwang was able to obtain from dubious sources, he had apparently succeeded in cloning human embryos, a world first.

"However, cultivating stem cells from cloned human embryos is much more difficult than simply cloning human embryos," said Kong Il-keun, bioengineering expert at Suncheon University.

The investigative panel on December 23 announced that Hwang had fabricated much of the data in the 2005 paper.

Hwang immediately tendered his resignation from the university but claimed that the five frozen cell samples would vindicate him.

Questions have also been raised about Hwang's other work including a 2004 paper also published in Science in which he claimed that he had achieved the first success in cloning human stem cells.

The 2004 paper has also been called into question after it was revealed that it contained photos from an unrelated paper.

The photos, claiming to show batches of the world's first cloned human embryonic stem cells, were apparently the same as those used in a research article by another South Korean team in a magazine called Molecules and Cells.

Source: China Daily