LG Uplus, the country's third-largest wireless carrier, said on Tuesday that the personal information of 180-thousand customers has been leaked.

An employee of the carrier confirmed the leakage in a phone call with Yonhap News, saying that the company asked the police to investigate the case and a probe is under way.

LG Uplus said that the leaked information includes the names, birth dates and phone numbers of customers, but financial data is safe.

The company reportedly first recognized the leak last Monday and requested the police and the Korea Internet and Security Agency to investigate the leak the next day.

The employee said that the company took about a week to disclose and acknowledge the leakage because it had to check uncertain data and identify customers whose information was leaked.

The company is notifying the affected customers by text message or e-mail. Customers can also check whether their information was included via the company's website.