The precise source of the hoax name remains unclear, but Mr. Erdogan also has enemies in the United States. Fethullah Gulen, an influential Muslim cleric whose millions of followers once supported Mr. Erdogan, now lives in self-imposed exile in Pennsylvania.

Once the Turkish media awoke to the news, journalists there took delight in reporting that their counterparts in the United States had apparently been “trolled” by a successful prankster.