Meanwhile, a segment of the news media that at one time was seen as a reliable supporter of the government has turned on Mr. Erdogan. Followers of the Muslim spiritual leader Fethullah Gulen, who is in self-imposed exile in Pennsylvania, have over the years secured top positions in the judiciary and the police and are said to be leading the corruption investigation. Several news media outlets are also affiliated with Mr. Gulen, and their coverage has been the most aggressive.

Mr. Erdogan and Mr. Gulen had once been partners in an Islamist political alliance, and together they pushed the military from its dominant position in politics through several trials on charges of coup plotting. Those prosecutions were led by the Gulenists, and the Gulen-affiliated news outlets were the biggest cheerleaders for the cases. Now that same judiciary is targeting Mr. Erdogan.

The coverage of the corruption scandal showed no signs of abating on Saturday, with thousands protesting Mr. Erdogan and his ruling party in Ankara, the Turkish capital. News reports showed labor unionists holding signs saying, “Shoulder to shoulder against fascism” and “This is just the beginning. The struggle continues” — slogans like those raised during the antigovernment protests last May and June.

Only a few miles away, in Parliament, lawmakers threw fists, kicks, water bottles, handbags and at least one laptop at one another as they argued over a bill that would allow the government to gain more power over the judiciary. Video on CNN Turk showed men in suits stepping on chairs and tables and yelling. One opposition lawmaker was treated at a hospital after a tablet computer was thrown at his head, and the president of a judges’ association was kicked by a lawmaker from the governing party, CNN Turk reported.

One columnist, Mahir Zeynalov, who writes for Today’s Zaman, an English-language daily affiliated with the Gulen movement, was recently sued by Mr. Erdogan for posts on Twitter that according to the complaint, “committed a crime by exceeding the limit of criticism.” Mr. Zeynalov’s posts, though, have been mostly about news events and the corruption investigation, and it was unclear what the prime minister had found offensive.

“I think I should only tweet about penguins from now on,” Mr. Zeynalov wrote on Twitter after the case was filed, referring to some television channels’ practice of broadcasting a documentary about penguins last spring rather than reporting on the antigovernment protests.

So even as the flow of leaks seems beyond Mr. Erdogan’s control, the government is doing its best to make life difficult for journalists reporting aggressively on the corruption allegations. During the long-running military trials, known as the Ergenekon and Sledgehammer trials, many of the most arresting details were reported by Mehmet Baransu, of the left-leaning daily Taraf.