A senior researcher of the disbanded Seoul cloning team Thursday accused Prof. Gerald Schatten at the University of Pittsburgh of concocting the stem cell paper fabrication, according to the prosecution.

Investigators said Kang Sung-keun, a top lieutenant of the country's disgraced cloning scientist Hwang Woo-suk, claimed Schatten knew about the cell contamination accident before authoring the article on patient-specific stem cells featured by Science last year.

Hwang's team has contended that six patient-specific cell batches, now all discredited, were destroyed by germs in Jan. 2005 and they failed to recover four of them.

``I heard Schatten suggest to Hwang that it would be okay to feature the four dead stem cells due to contamination in the Science article because they were really established,'' Kang was quoted as saying by prosecutors.

If true, this means Schatten played a role in cooking data for the acclaimed paper, in contradiction to a recent report claiming that Schatten is a victim of the Seoul team-led frauds, not an accomplice.

Earlier last week, a Pitt investigative panel vindicated Schatten, concluding that the biologist did not know information was faked.

Subsequently, Schatten was allowed to continue research at the university although with some sanctions.

Based on Kang's remarks, however, the Korean prosecution said that it will send an e-mail to Schatten to question the corresponding coauthor about the 2005 paper.

Meanwhile, a new allegation has erupted that Hwang might have created a cloned embryonic stem cell line, documented in his 2004 Science article, after all.

Shin Hyoung-doo at SNP Genetics, a local DNA test lab, made the point after conducting experiments with the stem cell in question at the request of the prosecution.

``Seoul National University argued that the cell was made through unisexual reproduction as eight of 48 nuclear polymorphic loci were not identical to a cell believed to be that of a donor,'' Shin said.

``But the university jumped to the conclusion as such phenomenon can happen in a cancerous cell. That shows the cell at issue might really be a cloned but damaged cell,'' he said.

A committee at the university said the cell featured in the 2004 Science paper is the result of unisexual reproduction called parthenogenesis: the growth of an unfertilized egg into an embryo.

The committee's conclusion that Hwang and his crew never created a cloned human stem cell further undermined the standing of the 53-year-old veterinarian.