A special adviser to the biological research center at the state-backed Riken institute said Saturday that he will resign, two days after an outside panel recommended disbanding the entity after two high-profile studies led by staff member Haruko Obokata had to be withdrawn from a British science journal.

But Shinichi Nishikawa, one of the four senior members of the Center for Developmental Biology in Kobe who were urged to quit Thursday by a committee investigating Riken, said he would not step down in line with the reform panel's recommendation.

"I decided to quit so I can speak freely. As an adviser, I need to speak on behalf of Riken," Nishikawa told Kyodo News.

Nishikawa was involved in recruiting Obokata, who became a research unit leader at the center in 2013.

Obokata was the lead author of two papers posted in the British science journal Nature in January that claimed to have successfully produced a new kind of stem cell. The so-called STAP, or stimulus-triggered acquisition of pluripotency, cells can develop into any type of tissue in mouses, her papers said.

Obokata recently agreed to retract the papers after discrepancies in them surfaced along with allegations of research misconduct.

The committee said Thursday that the CDB should be disbanded immediately because of its failure to prevent Obokata's misconduct.

The center was established in 2000 to carry out basic research on regenerative medicine and employs about 500 researchers.