Singapore: In an internal probing by the Novartis Pharma, it was revealed that its employees in Japan had failed to report about 10,000 cases of serious side effects caused by its drugs for leukemia and other diseases since 2002.

The company reported the findings to the Japanese Ministry of Health, Labor and Welfare and other health authorities, including the FDA, according to a news report. Novartis said that the cases were under investigation and were examined in detail.

The evidence supporting the side effects, were found to be shredded and online files, deleted. Novartis stressed that employees needed additional training in reporting adverse events.

Japan was a high money-making market for Novartis products, and the extent of the problem including the earlier scandal series, underscores the difficulties the drug maker may have in rehabilitating its image and, by extension, its business.