Nearly two weeks have passed since Kobayashi Pharmaceutical first reported health concerns over its beni kōji red yeast rice supplements — but tracking down its tainted products in the supply chain is proving to be extremely difficult.

An investigation into the cause of the health issues is underway, with partner companies attempting to recall products that could include the batch of beni kōji said to have caused kidney problems.

So far, as of Wednesday, the beni kōji supplements had been linked to at least five deaths, 188 hospitalizations and 1,058 doctor visits, with Kobayashi Pharmaceutical also receiving around 40,000 inquiries from consumers. In Taiwan, 11 people have reported feeling ill after consuming the drugmaker's supplements.