TOKYO, June 11 (Kyodo) — Tokyo prosecutors arrested a former employee of Novartis Pharma K.K. on Wednesday on a charge of manipulating clinical study data leading to exaggerated claims in advertising for one of the firm's drugs.

Nobuo Shirahashi, 63, is alleged to have manipulated cerebral stroke incidence and other data collected by a research team at the Kyoto Prefectural University of Medicine so that the team released a paper in favor of the Diovan blood pressure-lowering drug in 2011.

The arrest came after the prosecutors raided the Japanese sales arm of Swiss pharmaceutical giant Novartis earlier this year over its alleged use of clinical study reports for exaggerated advertising for the drug in violation of the pharmaceutical affairs law.

As a Novartis Pharma employee Shirahashi took charge of analyzing data from clinical tests comparing Diovan and other blood pressure-lowing drugs at five Japanese universities, including the Kyoto school, between 2002 and 2004.

The Kyoto team concluded Diovan was more effective than other blood-pressuring drugs in preventing stroke and angina based on the manipulated data from some 3,000 patients.

The Kyoto medical school's investigative panel reported the data manipulation last year.

The Jikei University School of Medicine in Tokyo, another of the five universities, also found manipulated data from a clinical study on the drug.

Novartis Pharma contributed a total of 570 million yen to the Kyoto Prefectural University of Medicine and the Jikei University School of Medicine between 2002 and 2012.

Novartis Pharma launched Diovan in Japan in November 2000 and achieved annual Diovan sales in excess of 100 billion yen in and after 2005. Cumulative Diovan sales reached 1.2 trillion yen by 2012.