MIAMI (CBSMiami/AP) —Immigration officials apologized to a U.S. Army veteran who discovered he was not a U.S. citizen.

A U.S. Citizenship and Immigration Services spokesman said Wednesday, May 21st the agency made a mistake and should have granted 58-year-old Mario Hernandez citizenship because of his Vietnam-era military service.

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On the same day, Hernandez was granted U.S. citizenship just after 1:00 p.m.

Hernandez had also worked for the Department of Justice’s Bureau of Prisons using a Social Security number he received when he arrived in the country as a child.

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He thought he was a U.S. citizen and repeatedly voted. It was only last fall when the Tallahassee resident sought a passport to take a cruise with his wife that he discovered the authorities did not list him as a citizen or a permanent resident. Suddenly, he was under federal investigation.

Hernandez said his first priority as a U.S. citizen will be to renew his voter registration, which he will do on Thursday since he lost that privilege when he was denied citizenship months ago.

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