Officials of Kanagawa Prefecture say nine more hard disk drives with taxpayers' personal information are still missing in addition to another nine drives that have been recovered. The 18 HDDs were auctioned away online by a worker of a recycling firm in violation of contracts.
The prefecture is urging the computer leasing company that handled the scrapping to find the missing HDDs.
Officials say each one of the drives has three terabytes capacity and contained files that included tax notification slips with the names of individuals and firms.
The prefecture rented the HDDs from Fujitsu Leasing and used them as data storage devices at its common server.
It returned the drives to the company in April for replacement with new ones.
Fujitsu Leasing ordered a contractor, Broadlink, to dispose of the HDDs and to make sure the data were completely destroyed, so that it could not be restored. But an employee allegedly sold all of them on an auction website.
A person who bought nine of the HDDs said although many of the files were unreadable, those containing taxpayers' personal details were accessible.
The prefecture says the nine other disks were auctioned off to three other bidders but they have not been retrieved.
Kanagawa Governor Yuji Kuroiwa apologized, saying that people in the prefecture must be feeling uneasy over a possible leak of personal information. He indicated that the prefecture will revise its contract with the leasing firm, so officials will be present the next time data are destroyed.
Saitama, Chiba and Ibaraki prefectures also rent hard disk drives from Fujitsu Leasing. They say they will ask the company if the disposal of their HDDs was properly managed. They say no leaks of personal information have been confirmed so far.