Names, social security numbers and date of birth details for 583,000 Candian students has been lost.
The information, which also includes contact information and loan details, was stored in an external hard drive that disappeared from Human Resources and Skills Development Canada (HRSDC).
The data was associated with people who received loans between 2000 and 2006. Also contained on the drive was personal information for 250 of the department's employees.
The loss was discovered during the investigation of the disappearance of a USB key containing the personal information of another 5000 Canadians.
“I want all Canadians to know that I have expressed my disappointment to departmental officials at this unacceptable and avoidable incident in handling Canadians' personal information,” Finance Minister Diane Finley wrote in a statement.
Finley requested an investigation by the Royal Canadian Mounted Police. The privacy commissioner is also investigating.
In the wake of the recent security breaches, HRSDC has banned portable hard drives within the department, and is assessing the security of portable devices. USB keys can no longer be connected to the department's computer network.