John Leyden writes the compromised database contains Turkish citizenship or residency information, including names, addresses and identification numbers.
The hackers responsible for the leak suggest the attack has been politically motivated and was intended to target President Recep Tayyip Erdogan, according to the report.
The reported incident, if confirmed, could be one of the biggest breaches in terms of the number of records affected, Leyden reports.
The leaked data has been published in a web page that displays some personal information related to Erdogan, former President Abdullah Gul and incumbent prime minister Ahmet Davutoglu, the report said.