CIBC Asset Management says a backup computer file containing information on almost half a million of its Talvest Mutual Funds clients has gone missing.

The company says the missing data was in a file that disappeared "while in transit between our offices." The file had personal and financial details on current and former clients of Talvest Mutual Funds, which is a CIBC subsidiary.

The information may have included client names, addresses, signatures, dates of birth, bank account numbers, beneficiary information and/or Social Insurance Numbers.   

Talvest says there's no indication that the missing backup file has been "inappropriately accessed," but says CIBC will be taking a number of precautions.

"We are in the process of contacting affected Talvest clients by letter to advise them of this issue and to detail the steps we are taking to safeguard their information," said Steve Geist, president of CIBC Asset Management.

Computer fraud expert Thomas Keenan from the University of Calgary said there's good reason for the company to alert their customers. "Because what's on there [the missing file] is everything you need to know to do identity theft," he told CBC News.  

The privacy commissioner of Canada, Jennifer Stoddart, announced that she is launching an investigation.

"Although I appreciate that the bank notified us of this incident and that it is working co-operatively with my office, I am nevertheless deeply troubled, especially given the magnitude of this breach, which puts at risk the personal information of hundreds of thousands of Canadians," Stoddart said in a statement.

Talvest has set up special phone lines for clients who want more information.

The report follows news of a potential corporate privacy breach that could affect as many as two million Visa credit card holders in Canada.

The owner of Winners and HomeSense stores warned Thursday that hackers gained access to its computer system and credit card numbers may have been improperly accessed.