Supermarket chain Seiyu GK is suspected of falsifying documents to allow more than 200 of its employees to take an examination to sell over-the-counter drugs, including for some who had never worked at a drugstore as required by law, health ministry sources revealed.

Unqualified Seiyu workers took the exam in at least 19 prefectures, including Tokyo and Osaka, and some who already received certification have been selling such medicines at Seiyu outlets, the sources said.

The local governments concerned are considering nullifying the employees' certification, they added.

Because certain drugs don't require a doctor's prescription but still must be sold by qualified employees due to possible health risks, entrants for the examination are required to have sold medicines for one year and for more than 80 hours per month under the supervision of qualified workers.

Before taking the exam, applicants are required to submit documents issued by their employers charting their work history. But Seiyu padded the number of hours its employees had worked in the documents it issued, and even falsified the records of some workers who had no experience selling drugs, the sources said.

"The documents were compiled by supervisors of the drug sales division at each Seiyu outlet, and our Tokyo headquarters did not detect the misstatements," one of the company's officials said.

The Tokyo Metropolitan Government received a tip this summer that some Seiyu employees who passed the examination might not have been qualified to take it in the first place, according to the sources.