Tokyo prosecutors charged Novartis Pharma K.K. and a former employee Tuesday with causing a medical research team to release data manipulated in favor of the firm's drug for treating high blood pressure in 2011.

The prosecutors also issued a fresh arrest warrant for the former employee at the Japanese unit of Swiss pharmaceutical giant Novartis AG on suspicion of causing the team to publicize false data again in 2012.

Nobuo Shirahashi, 63, who was arrested in June, was indicted for manipulating cerebral stroke incidence and other data collected by the team at the Kyoto Prefectural University of Medicine, causing the team to release a paper in favor of the Diovan drug in a medical journal in 2011.

Shirahashi has denied both allegations, the latter of which concerns research results the team posted on another medical journal's website in 2012, according to a source familiar with the matter.

The drugmaker was also charged with the alleged misconduct the former employee was engaging in under the pharmaceutical affairs law's clause against exaggerated advertising that sets a fine of up to ¥2 million.

"Novartis and (the Japanese unit) have already undertaken decisive action to address problems with the company's investigator-initiated trial research programs in Japan," David Epstein, global division head of Basel-based Novartis, said in a press release.

"We are committed to changing the culture (at the Japanese unit) and demonstrating ethical leadership among pharmaceutical companies in Japan," he said.

Shirahashi allegedly manipulated data and provided them to the team to falsely demonstrate the Diovan was more effective than other blood pressure medications for patients with coronary disease.