While the complaint does not disclose what country Mr. Lemma was working for, U.S. officials identified it as Ethiopia and described the suspected spying as narrow in focus.
In a statement, the State Department said it would work with intelligence agencies and conduct a review of the national security and foreign policy implications of the case.
According to a court filing, Mr. Lemma had been employed by the State Department since at least 2021, working during the evenings at a secure facility in Washington.
At the State Department, Mr. Lemma served as an information technology administrator in its intelligence arm, the Bureau of Intelligence and Research, known as I.N.R., and had access to classified systems, the filing said.
The intelligence arm handles some of the most sensitive American intelligence, which is used to better inform ambassadors and other senior diplomats.
State Department, Justice Department, of Intelligence, Research
Ethiopia, Washington, Eritrea