A Turkish newspaper published video footage on Friday which it said showed security forces discovering weapons parts being sent to Syria on trucks belonging to the MIT state intelligence agency.
The footage shows gendarmerie and police officers opening crates on the back of the trucks which contain what newspaper Cumhuriyet described as weapons and ammunition. Cumhuriyet said the video was from Jan. 19, 2014 but did not say how it had obtained the footage.
Reuters reported last week that witnesses and prosecutors have alleged that MIT helped deliver arms to parts of Syria under Islamist rebel control during late 2013 and early 2014, quoting a prosecutor and court testimony from gendarmerie officers.
Reuters could not verify the authenticity of the video footage, but the license plates on several of the vehicles matched those given in witness testimony seen by Reuters relating to the Jan. 19 search in the southern province of Adana.
President Tayyip Erdogan has said the trucks stopped that day belonged to MIT and were carrying aid to Turkmens in Syria. He has said prosecutors had no authority to search MIT vehicles and were part of what he calls a "parallel state" run by his political enemies and bent on discrediting the government.
The state-run Anadolu news agency said the Istanbul chief prosecutor's office had launched an investigation into Cumhuriyet's editor-in-chief under counter-terrorism laws after the footage was published on its website.
Syria and some of Turkey's Western allies say Turkey, in its haste to see President Bashar Assad toppled, let fighters and arms go over the border to hardline Islamist rebel groups in Syria.
Ankara has denied arming Syria's rebels or assisting hardline Islamists. Diplomats and Turkish officials say it has in recent months imposed tighter controls on its borders.
The witness testimony and the footage appear to contradict Turkey's denials that it sent arms to Syrian rebels.
Part of the Cumhuriyet footage seen by Reuters but not published on the newspaper's website shows gendarmerie and police officers surrounding the three trucks and a passenger car. One man is seen being brought down from the cab of one of the trucks, before being shown what appears to be a prosecutor's search warrant.
"Don't touch me, don't touch. You're going to see my ID," the man says as he is pulled from the cab.
"Don't treat me like you have captured a terrorist," another man tells a gendarmerie officer who has handcuffed him.
According to witness testimony and the prosecutor's report, the three trucks were allowed to continue their journey after MIT officials accompanying them threatened police.
More than 30 gendarmerie officers involved in the Jan. 19 search and the attempted search of another truck a few weeks earlier now face charges including military espionage and attempting to overthrow the government, according to an April 2015 Istanbul court document.
They deny the charges, according to their lawyers and their testimony.
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