TOKYO (AP) ― A Japanese government-funded laboratory said Tuesday it found that data in a widely heralded stem-cell research paper was falsified, holding the lead researcher responsible for the fabrication.

The research results from the Riken Center for Development Biology in Kobe, western Japan, were seen as a possible groundbreaking method for growing tissue to treat illnesses such as diabetes and Parkinson’s disease using a simple lab procedure.

Scientists at the institute said significant discrepancies in research published in January in scientific journal Nature 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 manipulation was used to improve the appearance of the results,” said Shunsuke Ishii, the head of the committee set up to investigate allegations the research was fraudulent.

The scientists 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 large 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.

The researchers said cells from other tissue of newborn mice appeared to go through the same change, which could be triggered by exposing cells to any of a variety of stressful situations.

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.

The panel would not comment on whether the modified cells, dubbed STAP cells, exist. STAP is short for stimulus-triggered acquisition of pluripotency cells. “That was not my mission,” Ishii said.