The health ministry will order a business suspension of around 15 days for a Japanese unit of Swiss pharmaceutical maker Novartis AG for not reporting serious side effects of its drugs, sources close to the matter said on Monday.

Tokyo-based Novartis Pharma K.K. would be the first pharmaceutical company in Japan to receive such an order from the Ministry of Health, Labor and Welfare for breaching the duty of promptly reporting serious drug side effects, according to the sources.

For Novartis Pharma, it would be the second administrative punishment over side-effect issues, after a business improvement order was issued last July for its failure to properly report side effects of two leukemia drugs.

The ministry plans to finalize the order after giving the company an opportunity to explain itself, the sources said.

Following an internal probe, Novartis Pharma admitted last December it failed to report a total of 3,264 cases of patient health problems possibly caused by adverse effects of 26 types of drugs sold by the company.

The drugmaker conducted the internal probe after it was found that some of the information about serious side effects learned by its sales representatives from hospitals did not reach an appropriate section in the company and was not reported to the government in a manner required by law.

Pharmaceutical firms are required to report significant drug side effects within 15 days or 30 days after they are found, depending on their seriousness.