Erkin Bulekbaev, who is also a television journalist, was arrested August 10 while he was filming a police operation at the Issykul Investbank building in Bishkek.
The opposition says the sentence is politically motivated.
The bank is at the center of a controversy over its leadership.
The bank’s director, opposition leader Bolot Baikojoev of the People's Will party, accuses the government of trying to remove him.