A former Los Alamos National Laboratory scientist was sentenced to five years in prison on Wednesday for passing classified U.S. nuclear weapons data to a person he believed to be a Venezuelan government official, the FBI said.

Pedro Leonardo Mascheroni, 79, a naturalized U.S. citizen from Argentina, pleaded guilty in June 2013 to several espionage-related offenses.

His wife, who is 71, was previously sentenced to a year in prison for her role in the same case, according to the FBI.