Turkish President Tayyip Erdogan during the TV interview.Twitter

A Turkish newspaper, known for its centre-left reportage, has earned the wrath of Turkey's President Tayyip Erdogan for publishing a video purporting to show the country's MIT intelligence agency sending weapons to Syria. 

The Cumhuriyet newspaper published the video on 29 May, in which it claimed that the trucks carrying arms and ammunition were sent by the intelligence agency to aid the Syrian rebels during January 2014.

The video corroborates previous reports that the MIT intelligence agency had sent arms to rebel-controlled parts of Syria during 2013 and 2014.

Erdogan has accused the newspaper of espionage and vowed that the editor-in-chief will "pay a heavy price."

"This slander and this illegitimate operation against the National Intelligence Organization [MİT] are, in a way, an act of espionage. This newspaper got involved in this espionage activity, too," Erdoğan said during an interview to public broadcaster TRT on Sunday, Turkey's Ankara news agency reported. 

The Turkish President has defended the movement of trucks by MIT claiming that they were carrying aid for Turksmen in Syria.

"Our National Intelligence Service gives humanitarian aid and logical support to Bayir Bucak Turkmen," Erdogan said.

"The individual who has reported this as an exclusive story will pay a high price for this," he threatened. 

Cumhuriyet's editor-in-chief Can Dundar took the byline for the front-page report headlined, "Here are the arms Erdogan says there were not."

Istanbul chief prosecutor's office has already launched a probe into the newspaper's editor. 

Dundar, in a tweet on Monday, said, "We are journalists, not civil servants. Our duty is not to hide the dirty secrets of the state, but to hold those accountable on behalf of the people". 

The news comes amidst reports that an intelligence officer previously part of Turkey's national intelligence agency was fighting as a member of Isis