A college professor and his wife, a college administrator, have been charged with being longtime illegal agents of Cuban President Fidel Castro, according to documents filed Monday.

Carlos Alvarez, a psychology professor at Florida International University, and his wife, Elsa Alvarez, were charged with acting as agents of Cuba without registering with the U.S. government as required, said the documents filed in U.S. District Court.

The two were scheduled to make an initial court appearance Monday before U.S. Magistrate Judge Andrea Simonton, according to the documents. An indictment further describing the charges was expected to be unsealed after that appearance, court officials said.

U.S. Attorney R. Alexander Acosta and representatives of the FBI and the Naval Criminal Investigative Service scheduled a news conference about the case later Monday.

Alvarez is identified on the Florida International Web site as an associate professor in the Educational Leadership and Policy Studies Department. His wife is described as a coordinator in the social work training program.

Carlos Alvarez didn't return two phone messages left at his office. A university spokesman didn't return several calls seeking comment.

The indictment marks the latest turn in the underworld of espionage between the United States and Cuba, much of which takes place in South Florida where thousands of Cuban exiles live.

In August, the convictions of five alleged Cuban spies were thrown out by a three-judge panel of the 11th U.S. Circuit Court of Appeals, which ruled that the five were unfairly tried because of intense publicity and community prejudice, along with inflammatory remarks by prosecutors.

The five, accused of being part of the Wasp Network of Cuban spies operating on U.S. soil, admitted being agents of Cuba but insisted they were spying on Cuban exiles opposed to Castro, not on the United States itself.

The full 11th Circuit has agreed to rehear the arguments on whether the five got a fair trial.