Gendarmerie private Utku Kalı, 26, had faced 25 years in prison for leaking four confidential documents about the attack, leading to their publication online, while he was performing his military service in the Black Sea province of Amasya.
The Amasya Court of Serious Crimes ruled for Kalı's acquittal in the eighth hearing of the case on Feb. 4.
Kalı was arrested on May 24, 2013 for leaking documents, belonging to the Gendarmerie Intelligence Department, claiming that the Syrian opposition group the al-Nusra Front, which has links to al-Qaeda, was planning a car bomb attack that might occur in Turkey.
The Samsun 3rd Court of Serious Crimes had later ruled for the release of Kalı pending trial in the second hearing.
A twin car bomb attack killed 52 people and injured 140 in Reyhanlı near Turkey's border with Syria on May 11, 2013. The attack was the biggest ever terrorist attack on Turkish soil at the time, but it remains unclear who was responsible.