By David Cyranoski

Cloning pioneer Woo Suk Hwang was sentenced to two years in prison at the Seoul Central District Court on 26 October, after being found guilty of embezzlement and bioethical violations but cleared of fraud.

Supporters of Hwang, a former professor at Seoul National University in South Korea, were pleased with the sentence, which is suspended for three years and half the length sought by prosecutors. The prosecution plans to appeal.

Hwang was once fêted for creating human stem-cell lines using cloned embryos derived from patients suffering from spinal-cord injury and other disorders (W. S. Hwang et al. Science 303, 1669-1674; 2004 and W. S. Hwang et al. Science 308, 1777-1783; 2005). The accomplishment, which promised an endless supply of stem cells genetically matched to patients, turned out to be bogus.

Hwang admitted in January 2006 to falsifying data, while maintaining that he had the ability to do what he had claimed. In South Korea, scientific fraud would be illegal only if Hwang had used fraudulent data to gain grants. Prosecutors argued that he duped two companies, SK Group and NongHyup, into supplying research funds. But according to media reports, the court rejected the allegations on the grounds that the firms provided money without expecting to benefit.

The court did, however, find Hwang guilty of buying human eggs in violation of the country's bioethics law and of embezzling 830 million won (US$700,000) of government money.

The Korea Times reported that the light sentence was motivated by judge Ki-ryul Bae's sympathy for Hwang's apparent dedication to Korean biotechnology and his stated remorse. Hwang will now be able to focus on his research career, which he has been rebuilding since he was indicted in May 2006 (see Nature 461, 1035; 2009).

Many researchers are not ready to welcome Hwang back. "It was not just one moment of weakness -- the degree of manipulation of the goodwill of people, particularly fellow scientists, made it more," says Alan Colman, a stem-cell scientist at the Institute of Medical Biology in Singapore. "The sad thing is that it's clear he is a talented experimentalist." Colman argues that Hwang should not be eligible for research funding from public sources for a prolonged period.

Researcher Ryuzo Torii of the Shiga University of Medical Science in Japan used large amounts of grant money, time and monkey eggs trying to reproduce Hwang's technique in non-human primates in 2004 and 2005. He says that forgiving Hwang and recognizing him as a researcher would be "a mistake".