The Riken research institute said Tuesday that former employee Haruko Obokata did not file an appeal in response to a report by its investigative panel that her debunked STAP cells were likely created instead from embryonic stem cells.

This means that fresh allegations of fabrications regarding her stem cell research, pointed out Dec. 26 by the institute's panel made up of outside experts, have been finalized.

Riken said Obokata was given a copy of the panel's findings last month and had until Monday to raise an objection.