A cyberhacker claims to have obtained the personal data of 1 billion Chinese residents in what could be one of the largest data breaches in history.

An anonymous user in a hacker forum using the handle “ChinaDan” offered to sell the large database last week for 10 bitcoin, worth about $200,000.

The user said the data was obtained from an unsecured Shanghai police database and was publicly accessible for a year. The user claimed the database contained such personal information as names, addresses, birth dates, national identification numbers and extensive criminal records.

U.S.-based cable news network CNN says it has verified the authenticity of more than two dozen entries from the sample provided by the seller, but could not access the original database.

Shanghai police officials have not responded to requests by news outlets to comment on the alleged data breach.

(AS/VOA)