UBS loses 15,500 customers' data

The Japanese arm of investment firm UBS is searching for a lost hard disk that contains the confidential data of 15,500 customers.

According to sources close to the company, the disk contains individual and company customer names, addresses, phone numbers and details of transactions carried out between 1994 and 2004.

Although the company has found the computer case that contained the disk, which was lost during a system upgrade in Tokyo and Hong Kong, it is still investigating whether the information has left the company building.

A spokeswoman for UBS said: "There is the possibility that a disk may have been lost. We are currently in the process of getting the aggregate picture of what has happened and we have informed the [Financial Services Agency] about the incident. They are not investigating - we are finding out what has happened."

But Japanese regulator, the Financial Services Agency (FSA), said it was eager to find out what happened and could launch its own investigation if UBS failed to answer questions.

An official from the FSA said: "Japanese banks have recently lost a lot of information. We've been asking why they lost the disk, what information was on it and what methods they have to prevent this. We've requested a report."

In April this year, the Japanese government passed a law to ensure companies protect their customers' data.

In March, Japanese bank Mizuho admitted losing details of 270,000 customer accounts.