SEOUL, South Korea — An academic panel investigating the work of South Korean researcher Hwang Woo-suk found that he faked his landmark claim to have cloned human embryonic stem cells — capping the spectacular fall of a man once lauded as a pioneer in the field.

The latest revelation today by an investigating panel at Seoul National University was sure to be a huge disappointment to scientists and patients alike. Hwang's breakthrough cloning claim had offered hope to millions of people suffering from debilitating diseases, such as Alzheimer's, Parkinson's and AIDS.

It followed a finding by the same panel last month that the Hwang's claim in 2005 to have developed 11 patient-specific stem cell lines was also false.

Hwang "did not have any proof to show that cloned embryonic stem cells were ever created," the panel said in a report, disputing claims in Hwang's 2004 paper in the journal Science. In the paper, Hwang said he had cloned a human embryo and extracted stem cells from it.

However, the panel upheld Hwang's claims last year to have created the world's first cloned dog, an Afghan hound named Snuppy. That achievement was not regarded as important as the cloning of human cells, however, as various animals had already been cloned.

Scientists hope to someday use human stem cells — master cells that can grow into any body tissue — to battle a number of diseases. Creating stem cells genetically matched to a specific patient would be a breakthrough because they would not be rejected by the patient's immune systems.

But despite years of research, Hwang was the only person to claim success in extracting the cells from an embryo.

"The 2004 paper was written on fabricated data to show that the stem cells match the DNA of the provider although they didn't," the report said.

The reputation of Hwang — once dubbed "The Pride of Korea" — has eroded steadily in recent months with increasing questions about his work.

In December, a devastating report by the university, where Hwang conducted much of his research, concluded that he had fabricated another article published in Science last year. The university's nine-member investigative panel said it could not find any of the 11 stem cell lines matched to patients, as Hwang had reported in that research.

Science has said it would retract that May 2005 paper and investigate Hwang's 2004 paper that claimed the first cloned human embryo.

Hwang had also come under fire for using eggs in his studies donated by junior researchers on his team. He conceded in November that two subordinate scientists had donated eggs without his knowledge and that other women were paid to take fertility drugs to produce eggs for research. Both practices are viewed as coercive and unethical in the West.