SEOUL, Sept. 19 (Yonhap) -- Hana SK Card Co., a South Korean credit card firm, said Monday that some 200 customers' personal information has been leaked, the latest in a series of security breaches that are spurring concern about private data protection.

The card firm, a joint venture between Hana Financial Group Inc. and SK Telecom Co., said the leaked data included "name, address and resident registration numbers" but did not cover information on financial transactions like customers' passwords and account numbers.

Hana SK Card called on police to investigate a telemarketing employee regarding the suspected leakage of personal data, it said.

But more personal information at Hana SK Card is estimated to have been leaked. Samsung Card Co., which also saw a similar data leakage last week, initially reported an estimated 20,000 customers were affected but later adjusted the number to 800,000.

Hana SK Card's data leakage spurred concern about lax online security for customers' private data at financial firms in South Korea.

Hackers struck the country's leading consumer finance firm Hyundai Capital Services Inc., leaking the data of some 1.8 million customers in April.

Early this year, the National Agricultural Cooperative Federation, or Nonghyup, was compromised in a separate hacking attack, which caused online transactions to fail.