The new technique was developed by researchers at the Riken Center for Developmental Biology in Kobe, Japan, and at Brigham and Women’s Hospital and Harvard Medical School in Boston. Haruko Obokata, the 30-year-old lead writer of the study’s two papers and a rising star in Japan’s scientific community, has became an overnight celebrity here and a symbol of the rising stature of female scientists.

Still, some experts quickly expressed caution, saying more needed to be known about the new approach. Caution turned to skepticism as researchers reported trouble in replicating the study’s results. Some of the photos used in the study were then called into question, as was wording that was found to be similar to that in an article published by different researchers almost a decade ago. Those questions prompted both Riken and Nature to begin separate investigations into the study’s integrity last month.

Riken has since released a more detailed description of procedures used in the study. But inconsistencies between those new procedures and the original papers only fueled more confusion and suspicion. Nature has said it is still investigating.

Dr. Wakayama said that the numerous questions raised left the authors with little choice but to retract the paper. Verification by independent researchers might also shed light on what went wrong in the study, he said.