World Bulletin / News Desk

Turkey has started an espionage investigation after a discussion between top officials on potential military action in Syria was leaked on YouTube, heralding a possible government crackdown on its political opponents after elections on Sunday.

The recording of the meeting between Turkey's intelligence chief, foreign minister and deputy head of the military was by far the most serious breach in weeks of highly sensitive leaks, a scandal which Prime Minister Tayyip Erdogan has cast as a plot to sabotage the state and topple him.

Erdogan and his aides have blamed the Hizmet Movement of U.S.-based congregation leader Fethullah Gulen, a former ally whose followers have influence in the police and judiciary, of running a "dirty campaign" of espionage to implicate him in corruption ahead of crucial nationwide municipal elections on Sunday.

"Tomorrow we will teach those liars and slanderers a lesson," Erdogan told a jubilant crowd of supporters in Istanbul's working class Kartal district on Saturday, vowing his ruling AK Party would triumph at the polls.

Police overnight briefly detained Onder Aytac, a prominent writer and journalist known to be close to the Hizmet Movement, on suspicion of having information about the bugging of the foreign ministry meeting.

CNN Turk meanwhile reported Erdogan's lawyers asked prosecutors to take precautionary measures to stop both Aytac and Emre Uslu, a newspaper columnist, academic and former senior anti-terrorism police official, from fleeing abroad.

Government officials declined to comment on whether an investigation into the leak had begun, saying any probe would be a matter for the judiciary. The state prosecutor's office could not immediately be reached for comment.

"DECLARATION OF WAR"

Senior officials said in February that Turkey would launch a criminal investigation into an alleged "parallel state" backed by Gulen, which they accuse of orchestrating the graft scandal and illegally tapping thousands of phones over years.

Erdogan's government has already reassigned thousands of police officers and hundreds of prosecutors in a purge after the corruption investigation burst into the open on Dec. 17 with the detention of businessmen and three ministers' sons, all of whom were later released. 

A senior government official on Friday described the crisis as "one of the biggest in Turkish history".

The bugged Syria meeting involved intelligence chief Hakan Fidan discussing possible military operations in Syria with Foreign Minister Ahmet Davutoglu, Deputy Chief of military Staff Yasar Guler and other senior officials.

Erdogan denounced the leak as "villainous" while Davutoglu called the posting a "declaration of war," an apparent reference to the escalating power struggle with Gulen.