Japan’s Riken Institute to announce that Stap cells cannot be reproduced

Some of Japan's top scientists have been unable to reproduce results of what was once billed as a ground-breaking stem cell study, but which spiralled into a scandal that included a respected researcher's suicide, reports said yesterday.

The government-backed Riken Institute will announce today that so-called Stap cells cannot be reproduced, writing the embarrassing final chapter of a study published in the journal Nature but later withdrawn, according to national broadcaster NHK.

"Cells with pluripotency could not be created under the method spelled out in the study," NHK said, citing unnamed sources.

Riken in January trumpeted how Haruko Obokata, now 31, had devised a simple method to re-programme adult cells to work like stem cells - the precursors that are capable of developing into any other cell that is in the human body.

The study was top news in Japan, where the photogenic Obokata, a Harvard-trained scientist, became a phenomenon.

But media attention soon grew into scepticism as doubts emerged about Obokata's papers on Stimulus-Triggered Acquisition of Pluripotency (Stap).