South Korea's disgraced cloning pioneer Hwang Woo-suk has apologised to the nation, in his first public appearance since his work was denounced as fake.
"I ask for your forgiveness," Dr Hwang told a televised news conference in the capital Seoul.
He said he would take responsibility for the errors, but claimed he had been deceived by junior researchers.
Dr Hwang was stripped of his national honours earlier this week, and his case is being investigated by prosecutors.
There is public concern about the $29m of government funding he received for his research.
Dr Hwang faced the media for the first time on Thursday, two days after his claimed breakthroughs in stem cell research were exposed as a fake.
He said he could not lift his head for shame and would take responsibility for failing to check the data that was produced by his researchers.
"The use of fake data... is what I have to take full responsibility for as first author. I acknowledge all of that and apologise once again," he said.
Feb 2004 Hwang Woo-suk's team declare they have created 30 cloned human embryos and extracted stem cells
May 2005 Team says it has made stem cell lines from skin cells of 11 people
Nov 2005 Hwang apologises for using eggs from his own researchers
15 Dec 2005 A colleague claims stem cell research was faked
23 Dec 2005 Academic panel finds results of May 2005 research were fabricated
10 Jan 2006 Panel finds 2004 work was also faked
But he insisted that most of the fabrications were carried out without his knowledge, by collaborators on the project.
He said his lab had produced about 100 cloned human embryos, but the hospital responsible for developing them into stem cells had deceived him about the results.
He speculated that the head of the hospital responsible may have wanted personal revenge against him.
Dr Hwang also continued to insist that he had the technology to use cloning to create human embryonic stem cells genetically matched to patients.
"I think we can create patient-specific stem cells in six months if eggs are sufficiently provided," he said.
Scientists hope to use such technology to treat genetic conditions such as diabetes and Parkinson's, by allowing patients to grow replacement tissue using their own stem cells.
A final report from experts at Seoul National University, published on Tuesday, said that Dr Hwang had faked his most famous work, the production of a stem cell line taken from cloned embryos.
The panel had previously rejected another of his landmark claims - to have produced individually tailored stem cells.
But it did conclude that Dr Hwang produced the world's first cloned dog, an Afghan hound called Snuppy.
Seoul National University, where Dr Hwang was a professor, has already apologised for the fraud.
The South Korean government stripped Dr Hwang on Wednesday of the title "top scientist", which entitled him to at least 3bn won ($3m) in state funding a year for five years.
Prosecutors were also sent to the office of the Seoul university panel that investigated his case, to collect scientific materials which may serve the basis of any criminal prosecution, according to Yonhap news agency.
Charges against Dr Hwang and his team could include fraud and embezzlement.