Data in a widely heralded stem-cell research paper was falsified, a Japanese government-funded laboratory said today, as the lead researcher denied any wrongdoing.
The research from the Riken Centre for Development Biology in Kobe, western Japan, had been hailed as a possible breakthrough for growing tissue to treat illnesses such as diabetes and Parkinson's disease using a simple lab procedure.
But significant discrepancies in research published in January in the scientific journal Nature led a panel of scientists at Riken to conclude that they stemmed from falsified data.
They said researcher Haruko Obokata, the lead author of the paper in Nature, had manipulated or falsified images of DNA fragments used in the research.
"The investigation committee has concluded that Ms Obokata is responsible for manipulation and therefore for research malpractice," said Shunsuke Ishii, the Riken scientist who led the committee charged with investigating allegations that the work was falsified.
Ms Obokata, in a statement also issued through Riken, vehemently objected to the committee's findings.
"I was outraged and shocked by the committee's report," she said. "I cannot accept the finding, and I intend to make an appeal to Riken in coming days."
Juliette Savin, a spokeswoman for Riken, said she could not comment on Ms Obokata's employment status.
Last month, Riken director Ryoji Noyori said misconduct by researchers would result in "strict disciplinary action as stipulated by our own regulations".
The institute said it would take months to determine whether the stem cell findings are valid regardless of any questions about the data. Ms Obokata asserts the findings are genuine.
The dispute over the research is a setback for government efforts to market Japan's research and development expertise as a 21st century industry needed to revitalise the country's manufacturing.
Prime Minister Shinzo Abe has made greater gender equality and female advancement in the workforce a plank of his economic revival strategy for Japan. But the recognition of Ms Obokata, a fashionable young woman, as a leading scientist still made waves in conservative, male-dominated Japan.
The scientists investigating the case said three other co-authors of the papers had not falsified the data but were still "gravely responsible" for failing to fully verify the research findings. The discrepancies in the data showed up as anomalous lines in an image of DNA fragments.
Researchers in Boston and Japan conducted the experiments in using a simple procedure to turn ordinary cells from mice into stem cells by exposing cells from spleens of newborn mice to a more acidic environment than they are used to.
Cells from other tissue of newborn mice appeared to go through the same change if exposed to any of a variety of stressful situations, the researchers said.
Scientists hope to harness stem cells to replace defective tissue in a wide variety of diseases. Making stem cells from a patient would eliminate the risk of transplant rejection.