Recordings of Recep Tayyip Erdogan’s alleged conversations, suggesting corruption, have been leaked in recent weeks, dealing him a major blow ahead of this month’s local elections.
Mr Erdogan said his government is determined to stem the leaks he insists are being instigated by followers of an influential US-based Muslim cleric.
He has accused supporters of Fethullah Gulen of infiltrating police and the judiciary and of engaging in “espionage”, saying that the group even listened in on his encrypted telephone lines.
The Gulen movement denies involvement.
Mr Erdogan said: “We are determined on the issue, regardless of what the world may say. We won’t allow the people to be devoured by YouTube, Facebook or others. Whatever steps need to be taken, we will take them without wavering.”
Asked if the steps could include shutting those sites down, Mr Erdogan replied: “That included. Because these people or institutions are (using social media) for all kinds of immorality, all kinds of espionage and spying.”
Mr Erdogan has acknowledged some of the leaked recordings, including two where he is heard meddling in a court case against a media proprietor and in a tender for the construction of warships.
He has rejected as “fabrication” five recordings purported to be of him instructing his son to dispose of large amounts of money on the day that prosecutors and police carried out raids on the homes of three former ministers’ sons as part of a corruption and bribery investigation.
Mr Erdogan, claiming to be a victim of a Gulen-orchestrated plot, has taken a series of steps to stall the corruption investigation, including removing hundreds of police officers and prosecutors and expanding government controls over the judiciary and the internet.
The new internet restrictions sparked violent protests in Istanbul.