Kobayashi Pharmaceutical trying to identify 'unintended substance'

Japanese drugmaker Kobayashi Pharmaceutical is rushing to identify what it calls an "unintended substance" that may have been included in one of the ingredients in its health supplements.

The company says the substance is similar to something produced by mold.

Some people developed kidney problems or other health issues after taking the drug maker's supplements containing "beni-koji" -- rice fermented with red yeast. It has been confirmed that four people have died. A total number of 93 hospitalizations have also been confirmed so far.

Kobayashi Pharmaceutical says its examination into one of its products, Benikoji CholesteHelp, has found that material included in the beni-koji manufactured between last April and December could have contained an "unintended substance."

The drugmaker says it is currently analyzing the substance, and will look into why the substance was produced and how it affects people's health.

The company is scheduled to hold a news conference on Friday. It is expected to explain the progress in its examination and its recalls of products containing beni-koji.