Japanese health supplement maker Kobayashi Pharmaceutical said Friday it was probing 76 more deaths possibly linked to its tablets containing red yeast rice, or "beni koji", meant to lower cholesterol.
It deepens a scandal that erupted earlier this year when the company said it was probing five deaths potentially linked to the over-the-counter products after dozens of customers reported kidney problems.
"Even if the direct cause of hospitalisation or death was not kidney-related disease, it has become clear that there are a variety of cases, including cases in which beni koji-related products may have caused harm somehow and had some indirect impact," Kobayashi said in a statement.
Of the five initial deaths under investigation, the company said it now knows one did not consume red yeast rice.
Fermented with a mould culture, the ingredient has been used in food, alcoholic drinks and folk medicines for centuries around East Asia.
"We have received 1,656 inquiries from individuals who have sought medical attention, and have 76 cases under investigation over (a causal) connection to the deaths," in addition to the original four, it said.
Kobayashi Pharmaceutical had announced on March 22 that it was recalling three kinds of over-the-counter tablets containing beni koji.
It later said it had detected a potentially toxic acid produced by the mould at one of its factories, and government officials inspected the firm's facilities.
Kobayashi Pharmaceutical is a household name in Japan, offering a wide range of health-related products, and the scandal has been top news in the country.
On Friday, Kobayashi said it was yet to identify the exact cause and scope of the health damage, including whether it could have harmed organs other than kidneys.