Hackers have posted a database online that allegedly contains the personal information of nearly 50 million Turkish citizens in what is one of the largest public leaks of this scale.
The Associated Press was able to partially verify the authenticity of the leak.
The entries include data such as national ID numbers, addresses, birth dates and the names of parents.
The Associated Press ran 10 non-public Turkish ID numbers against names contained in the dump. Eight were a match.
The leaked database contains 49,611,709 entries and divulged considerable private information, putting people at risk of identity theft and fraud.
The site appears to be hosted by an Icelandic group that specialises in divulging leaks.
In an era where hackers frequently gain access to sensitive information, the Turkish government is not alone in facing a major breach.
Among the most serious recent incidents, the US government's Office of Personnel Management (OPM) revealed in April 2015 that hackers gained access to the personal information of more than 22 million US federal employees, retirees, contractors and others, and millions of sensitive and classified documents.
US officials believe a Chinese espionage operation infiltrated OPM's records.