... and was caught by Der Spiegel! From Wikipedia: "On 19 December 2018, Der Spiegel made public that Relotius had admitted that he had "falsified his articles

... and was caught by Der Spiegel! From Wikipedia: "On 19 December 2018, Der Spiegel made public that Relotius had admitted that he had "falsified his articles on a grand scale", inventing facts, persons and quotations in at least 14 of his stories in Der Spiegel, an event now being referred to as Spiegelgate. The magazine uncovered the fraud after a co-author of one of Relotius's articles about a pro-Trump vigilante group in Arizona conducting patrols along the Mexico–United States border, the Spanish-born Spiegel journalist Juan Moreno, became suspicious of the veracity of Relotius's contributions and gathered evidence against him."