The federal government is being sued over the loss of a portable hard drive containing personal information about more than half a million people who took out student loans.

Merchant Law Group is filing class-action lawsuits in Calgary and Winnipeg, and says it plans to file more in other parts of the country.

Human Resources and Skills Development Canada said last week the device contained data on 583,000 Canada Student Loans Program borrowers from 2000 to 2006.

The missing files include student names, social insurance numbers, dates of birth, contact information and loan balances of borrowers, as well as the personal contact information of 250 department employees.

Borrowers from Quebec, Nunavut and the Northwest Territories during this time period are not affected.

No banking or medical information was on the portable device.