The chopper, whose passengers included seven policemen, one judge and one non-commissioned officer, crashed at around 0840 GMT in the eastern province of Tunceli, the governor's office said in a statement.
The other three people on board were crew members.
No signals were received from the Sikorsky helicopter approximately 10 minutes after it took off. It is believed to have crashed because of unfavourable weather conditions, according to the statement.
In March, seven people were killed, including four Russians, when a privately owned helicopter crashed in Istanbul after hitting a television tower.