Japanese scientist ends life

A Japanese scientist and expert on embryonic stem cells - embroiled in a recent stem-cell research controversy - committed suicide Tuesday, media reports said.

The research papers by Yoshiki Sasai, deputy director of the Riken Center for Developmental Biology, appeared in the journal Nature in January and showed a revolutionary method of creating stem cells.

The research was challenged and Nature retracted research papers in July, stating they contained inaccurate data, the Wall Street Journal (WSJ) reported.

Sasai was found in a biomedical research institution adjacent to the Riken center in Kobe, western Japan.

The controversy had put the reputation of Riken, one of Japan's leading research institutions, at risk.

He worked with lead author Haruko Obokata on the two stem-cell papers.

Sasai's career took a heavy blow from the controversy over the Nature studies, the WSJ report said.