Tokyo - A leading Japanese scientific institute said Tuesday it found fraudulent data in a high-profile stem cell research by a group of scientists, including its own.
The government-funded Riken institute held the lead researcher Haruko Obokata of its Centre for Developmental Biology responsible for the falsification.
A Riken panel found two sets of images of DNA used in their studies published in the British journal Nature in January were either manipulated or fabricated by Obokata.
Obokata rejected the report's conclusions as unacceptable.
"I'm filled with anger and surprises," she said.
Riken said three other co-authors of the papers had not fabricated data, but were "gravely" responsible for failing to verify the contents.
Riken said it would take about a year to verify whether the STAP(stimulus-triggered acquisition of pluri potency) cells exist.
The team based at Riken and Harvard University found an apparent new way to create stem cells more simply and quickly by dipping them in acid.
The studies attracted global attention, but questions were raised about a number of irregularities in the papers, including the images used in the research.