A panel from Seoul National University investigating Hwang's work said last week at least nine of the 11 patient-specific stem cell lines reported this year in the journal Science were fabricated. On Thursday, the panel said the remaining two were also faked.
"The panel couldn't find stem cells that match patients' DNA regarding the 2005 paper and it believes that Hwang's team doesn't have scientific data to prove that (such stem cells) were made," Roe Jung-hye, the university's dean of research affairs, told reporters.
"The bottom line is that it's a major disaster to our whole field because the expectations were so high and now we are back to square one," said Joseph Itskovitz, a stem cell researcher.
The South Korean government, which last week strongly suggested it would stop supporting Hwang, reacted cautiously.
"We don't have an official position over today's report as Seoul National University's investigation is still under way," said Nam Sang-mun, a spokesman for the Science and Technology Ministry.
Hwang filed a complaint with prosecutors last Friday that some of the stem cell lines his team created were replaced by those made at Seoul's Mizmedi Hospital, which had collaborated with his research team.
Roe said while the university's investigation found that some of Hwang's purported stem cell lines originated from Mizmedi, probing any possible switch is beyond the scope of the panel.