South Korean cloning researcher Hwang Woo Sook was barred Friday from returning to human stem-cell research, two years after a scandal over manipulated data in studies in which Hwang had claimed to be the first to clone human stem cells.

The Health, Welfare and Family Affairs Ministry in Seoul said it rejected the application of Hwang's lab to begin such research.

"The decision was made as Hwang still stands on trial on charges that he violated the nation's bioethical laws and was fired from his school for paper fabrication and other unethical problems in obtaining eggs in relation to his research on stem cells in 2006," the ministry said.

Hwan's research lab voiced its disappointment over the decision. "There is no clause in the regulation on bioethics that states the proposed study must be disapproved when its chief researcher is on trial," the Korea Herald newspaper quoted a lab spokesman as saying.

Hwang had once been hailed as a national hero and an international medical pioneer after publishing 2004 and 2005 studies in which he not only claimed to have cloned human stem cells but also to have developed patient-specific stem cells.

The research was considered to hold the key to potential treatments, even cures, for such conditions as heart failure, diabetes, and Alzheimer's and Parkinson's disease because embryonic stem cells have the potential to develop into any other cell in the body.

However, in January 2006, Hwang's research team was found to have fabricated lab test results for those studies. Hwang was fired by Seoul National University and charged with fraud, misuse of millions of dollars in research grants and violation of bioethics laws for allegedly purchasing human eggs from donors.

That same year, he founded his own private laboratory in Seoul, the Suam Biotechnology Research Centre, which has been doing animal cloning.