A man who until recently was considered the world's greatest cloning expert has apologised to fellow South Koreans after much of his research was exposed as fake.
A panel of peers who examined the work of Professor Hwang Woo-suk has concluded that results from nine of the 11 stem cell lines he said he had created were deliberately falsified.
The investigators called it a grave act that damaged the foundations of science.
Professor Hwang said he was sorry for the shock and disappointment he had caused and was resigning from his post at Seoul National University.
