Japan's Kobayashi Pharmaceutical's president and chairman resigned on Tuesday following an investigation revealing 80 deaths potentially related to dietary supplements used to reduce cholesterol levels.

The pharmaceutical firm acted with an "insufficient sense of urgency" and failed to prioritize patient safety, according to an external report released by the company's board on Tuesday. The report, conducted by external lawyers, showed that Kobayashi Pharmaceuticals started to receive reports of kidney-related problems from physicians in mid-January and early February.

The health issues originated from the pharmaceutical company's over-the-counter tablets, containing red yeast rice, or "beni koji," fermented with a mold culture. 

Kobayashi Pharmaceutical released a statement concerning President Akihiro Kobayashi and Chairman Kazumasa Kobayashi's resignation, saying the decision was made "to clarify executive responsibility over a series of actions by our company related to the ‘beni koji’ issue."

Mold produced a harmful acid

Red yeast rice is a common ingredient used in food, alcoholic drinks, and folk medicine in the East Asian region, and has been proven to improve cholesterol levels. However, medical studies have also warned that the constituent poses a risk of organ damage depending on its chemical makeup.

In the case of the dietary supplements, the mold produced a potentially harmful acid that resulted in customers returning three brands of tablets in March due to kidney-related issues. The pharmaceutical company then conducted an internal probe, discovering a total of 80 deaths were potentially linked to kidney problems caused by the dietary supplements.

“Kobayashi Pharmaceutical had never before received multiple reports of serious cases from doctors in such a short period of time," the team of lawyers said on Tuesday, stressing that the company should have withdrawn the products and reported the cases. However, the action was only taken after the investigation was conducted.

“Despite this, the company did not immediately consider disclosure to consumers, acting with an insufficient sense of urgency," the lawyers added.

The government also criticized the firm's delayed reporting of cases, describing their lack of transparency as "extremely regrettable." 

Although Akihiro Kobayashi will continue to play a role in managing the company's compensation-related issues to claim responsibility for the harm, the firm revealed that its new president is their former head of sustainability policy, Satoshi Yamane.