British Transport Secretary Ruth Kelly told Parliament that the storage device contained the names, addresses and telephone numbers of the student driver's candidates.
Iowa City-based Pearson Driving Assessments, a contractor employed by the Driving Standards Agency, was in possession of the drive, lost in May. Officials, though, do not believe anyone could access the data.
“The hard disk drive was also…formatted specifically to fit Pearson configuration drives and as such is not readily usable or accessible by third parties,” Kelly said. “Pearson has confirmed that there is no external indication of the drive's contents.”
In light of the incident, Pearson now transfers data electronically, she added.
This is the second major data breach to impact the U.K. in recent weeks. Last month, two computer disks belonging to the nation's tax and welfare department were lost. They contained the names, addresses and national insurance numbers for some 25 million adults and children.