Japanese government health officials raided a factory making health products on Saturday that they said had killed at least five people and hospitalized more than 100 people.

The raid, which saw about a dozen men in dark suits solemnly walk into Kobayashi Pharmaceutical’s Osaka plant, was widely reported on Japanese television news, including public broadcaster NHK.

The exact causes of these illnesses, which include kidney failure, are poorly understood, the company said. Investigations into these products are ongoing in collaboration with government health authorities.

These supplements all use “benikoji”, a type of red mold. Kobayashi Pharmaceutical’s pink pill “Benikoji Choleste Help” is promoted as helping to lower cholesterol levels.

Kobayashi Pharmaceuticals, based in the western Japan city of Osaka, said it sold about 1 million packs in the past three fiscal years. It also sells Red Trail to other manufacturers and some of its products are exported. These supplements can be purchased at pharmacies without a doctor’s prescription.

Although Honggulu has been used in products for many years, reports of health concerns surfaced in 2023.

Kobayashi Pharmaceutical President Akihiro Kobayashi apologized for not taking action sooner. The recall was carried out on March 22, two months after the company received an official medical report on the problem.

On Friday, the company said five people had died and 114 people were being treated in hospital after taking the product. Japan’s Ministry of Health, Labor and Welfare said the supplements were a cause of death and illness and warned that the number of people affected could rise.

Some analysts blame recent deregulatory moves that have streamlined and accelerated approvals of health products to spur economic growth. But deaths from mass-produced products are rare in Japan because government inspections of consumer goods are relatively strict.

The government has ordered a review of the approval system for supplement-related illnesses. The report is due in May.