A major Japanese drugmaker said Tuesday it was investigating one death from kidney dysfunction potentially linked to health supplements recalled last week by the firm.

It comes a day after the drugmaker, Kobayashi Pharmaceutical, said it was aware of 26 cases of people being hospitalised in relation to the prescription-free supplements.

The three recalled products -- "beni koji choleste help" and two similarly named supplements -- contain an ingredient called "beni koji", made by fermenting rice with yeast, which is supposed to lower levels of bad cholesterol.

"We're now aware of one instance where there is a potential causal link between a death and our product," Kobayashi Pharmaceutical said in a statement.

"We are currently investigating the link, and what happened," it said, offering its "deepest apologies".

The Osaka-based drugmaker voluntarily recalled the three products on Friday following customer complaints about kidney problems.

It said on Monday that it had not reached a conclusion on a link between the health problems and its supplements, but said analysis had found a possibility that the beni koji contained "ingredients we had not intended to include".

Kobayashi Pharmaceutical says it has supplied beni koji to around 50 other firms worldwide, according to public broadcaster NHK.

Japanese media reports said Kobayashi executives would visit the victim's family on Tuesday.