Japan's Ministry of Health, Labour and Welfare today asked public prosecutors to investigate a possible criminal violation of drug marketing laws by the Japan subsidiary of the giant Swiss pharmaceutical firm Novartis. The ministry says the company may have exaggerated the benefits of its hypertension drug valsartan.

Last July, Novartis Pharma admitted that a former employee created a conflict of interest by participating in clinical studies of valsartan, sold under the trade name Diovan, conducted by five Japanese medical schools while concealing his affiliation with the company. Several of the studies were retracted after investigations by the medical schools and the health ministry turned up data manipulation that skewed results. Novartis Pharma advertisements had pointed to the studies as showing that the use of Diovan reduced the risk of heart attack and stroke in hypertension patients better than alternative medications. According to Japanese press reports, potential fines could be just $20,000, but there is a small chance executives could face jail sentences.

Also today, Novartis Japan posted a statement in Japanese on its website acknowledging the investigation and apologizing "to patients, their families, health care workers and citizens for causing great worry and trouble." As in previous statements, Novartis pledged to fully cooperate with authorities but did not admit any wrongdoing.