The government-funded Riken institute announced Thursday that it will not reinvestigate the controversial papers on so-called STAP cells, finalizing its conclusion that their main author, stem cell scientist Haruko Obokata, is guilty of research misconduct.

Riken also formally recommended withdrawing one of the two papers Obokata wrote with a team of Japanese and U.S. scientists that were published in the British journal Nature in January.

“I understand that (Riken’s) investigative panel has reached the conclusion by carefully considering the matter,” Riken President Ryoji Noyori said in a statement. “Based on its report, we have decided not to conduct a reinvestigation, have notified (Obokata) of our conclusion and have recommended one of the papers in question be withdrawn.”

Minoru Yonekura, a Riken director in charge of compliance, told a news conference Thursday that the institute set up a disciplinary committee at a meeting of directors the same day to deliberate the penalties for Obokata and her fellow researchers at Riken.

Riken can take a variety of actions against employees found to have engaged in misconduct, such as pay cuts, suspension from work, forced resignation and disciplinary discharge. The disciplinary actions could affect not only Obokata, but other Riken researchers, including Yoshiki Sasai, deputy director of the Center for Developmental Biology, who co-authored the STAP papers.

In a 21-page report concerning the allegations against Obokata, Riken said the conclusion of the April 1 report by an in-house panel that found Obokata guilty of two counts of research misconduct remains solid, and that a reinvestigation “was not necessary.”

Obokata has insisted her findings are valid, and that any mistakes were made without “malicious intent.”

But Riken’s final report said “malicious intent” can be proved with the “intentionality” of the acts, even when there are no “strong intentions to inflict damage, such as through camouflage.”

Obokata’ lawyer, Hideo Miki, said he was “extremely displeased” with the institute’s conclusion. He added that Obokata was “at a loss for words” when she was informed of Riken’s final decision Thursday morning.

“We are extremely displeased with the fact that (Riken) reached a hasty, slipshod conclusion,” he told reporters who stormed his office in Osaka. “We cannot possibly accept it.”

On Wednesday, Miki said that Obokata mistakenly submitted incorrect images with the Nature articles while under pressure to publish them as quickly as possible.

“I was anxious to complete the papers due to concern that someone could overtake me and make a new discovery unless I published the papers quickly,” Miki quoted Obokata as saying Wednesday in her written explanation to her employer, Riken.

The papers on STAP cells — short for stimulus-triggered acquisition of pluripotency — attracted global attention for proposing that the cells could be used to grow any body tissue in mice.

However, suspicions arose soon after the papers were published in Nature — many from anonymous research bloggers — prompting Riken to launch an investigation into the alleged acts of misconduct on Feb. 14.

Information from Kyodo added