Haruko Obokata, 30, was admitted to hospital yesterday because her "mental and physical condition is unstable," her lawyer Hideo Miki told reporters.
But an official at his office said she is still planning to hold a news conference tomorrow.
The official added that Miki will file a formal complaint later today with the respected Riken Institute, which sponsored the study, and has since discredited the research behind it.
The complaint comprises a demand for reinvestigation of the issue and retraction of the probe's conclusion that her study was fabricated.
More From This Section
That could significantly boost the search for a ready supply of transplant tissues, offering much-needed progress in the battle against all manner of degenerative diseases.
A rash of magazine pieces and television shows celebrated a rare success for a young Japanese woman in a field largely dominated by middle-aged men.
But weeks after her team's research appeared, questions began to emerge over their methodology, with other scientists unable to repeat the experiments and claims that images used in public presentations were doctored.
Riken launched an inquiry into the credibility of the data used to support the paper, which was also published in the prestigious scientific journal Nature.