South Korean prosecutors raided the home of disgraced stem-cell scientist Hwang Woo-suk Thursday in their investigation into his research fraud, local media reported.

It was the second time prosecutors searched Hwang's home in southern Seoul to seize evidence after the country's top university concluded he had faked research results once hailed as breakthroughs in finding cures for hard-to-treat diseases like Alzheimer's and diabetes.

The prosecutors also raided eight other homes and offices of Hwang's former colleagues, Yonhap news agency reported.

Prosecutors were not available for comment.

Also Thursday, a presidential advisory committee on bioethics said in an interim report on Hwang's research that he had used 2,221 human eggs donated by 119 women, and that 62 of the women were paid for it. Hwang had earlier said he used only a small number of eggs.

"There were serious ethics problems" in Hwang's research, Lee Dong-ik, a professor at Catholic University of Korea and a member of the National Bioethics Deliberative Commission, told The Associated Press.

Lee said Hwang is believed to have coerced junior researchers in his lab into donating their eggs for the research, a practice widely considered unethical.

Last month, Seoul National University said Hwang's team fabricated data in papers published in 2004 and 2005 that purported to show they created stem cells from the world's first cloned human embryos. The journal Science has since retracted both papers.

Hwang publicly apologized for faking data, but claimed he was deceived by fellow researchers. He said some of the stem cells at his lab had been maliciously switched and called for prosecutors to investigate.

Prosecutors said last week that their own DNA tests failed to find any evidence Hwang created stem cells that genetically matched specific patients as he claimed in the 2005 paper, corroborating the university probe.

State auditors questioned Hwang last Friday about possible misappropriation of state funds. He has not yet been questioned by prosecutors.

Through last year, Hwang received $42.2 million in government funds for his research as well as $4.35 million from private foundations, according to the Board of Audit and Inspection.

It is not yet clear whether Hwang or any of his former collaborators could face fraud charges, a crime punishable by up to 10 years in prison.

Hwang, a veterinarian, was stripped of his professor post at Seoul National University and is awaiting punitive action by the university's disciplinary committee. Although Hwang has offered to resign his faculty position, he still retains the title of professor of veterinary medicine.

The committee is expected within weeks to deliver its decision on what action to take against Hwang and six other professors on his team.