Ben Conery

They wouldn't have looked out of place at a yacht club with him dressed in a blue blazer and khakis and her sporting a soft tan but federal authorities say the appearance of Walter Kendall Myers and his wife, Gwendolyn Myers, belied a darker truth: For three decades, the couple spied for the Cuban government.

Mr. Myers, a 72-year-old former State Department analyst with a top-secret security clearance, and Mrs. Myers, 71, appeared in federal court to answer charges of conspiracy to act as illegal agents of the Cuban government, passing classified information, and wire fraud. They each face 35 years in prison if convicted.

They pleaded not guilty to all charges during a hearing before U.S. Magistrate Judge John M. Facciola.

Mr. Myers, who authorities say was known as "Agent 202" to his Cuban handlers, rubbed the corner of his white mustache while thumbing through court documents during the arraignment. Mrs. Myers, who authorities say was called "Agent 123," and "Agent E-634," sat with her back completely straight but could not read the charges against her because her glasses had been left in the couple's District apartment. They were arrested at a hotel in Washington.

They will be held without bond until a detention hearing Wednesday morning, when a judge will determine whether they can be released before trial.

Prosecutors want to keep the Myerses in jail, arguing that they are serious flight risks.

Assistant U.S. Attorney Michael Harvey said the couple has $500,000 in a brokerage account and owns a family compound in Nova Scotia. He said Mr. Myers told an undercover FBI agent about the couple's desire to move to Cuba, saying "our idea is to sail home."

The couple's lawyers, Tom Green and Bradford Berenson, declined to comment. Three of their children from previous relationships who attended the arraignment said they were "shocked," but declined further comment.

"I'm shocked and saddened by the allegations," a former colleague of Mr. Myers' told The Washington Times, who asked to remain anonymous. "Kendall was a highly respected analyst of European affairs and well liked."

Mr. Myers worked for the State Department for nearly three decades before retiring in 2007. He worked as a European analyst in the Bureau of Intelligence and Research during his last seven years at the State Department.

Authorities say the Myerses' suspected spying was not motivated by cash, but by a deep support for Cuba.

Mr. Myers first traveled to Cuba in December 1978 for "unofficial personal travel for academic purposes."

Writing about his trip to Cuba in a 1978 diary entry, Mr. Myers criticized what he considered "American imperialism" and praised then-Cuban President Fidel Castro, calling him "one of the great political leaders of our time," crediting him with helping "the Cubans to save their own souls."

"I can see nothing of value that has been lost by the revolution," Mr. Myers wrote, according to diary excerpts included in an FBI affidavit detailing the allegations against the couple. "The revolution has released enormous potential and liberated the Cuban spirit."

Six months after that trip, according to court documents, the Myerses met with a Cuban and agreed to become spies. The FBI said the operative told Mr. Myers to pursue a job at the State Department or the CIA.

Authorities say the Myerses ultimately passed on more than 200 sensitive or classified State Department intelligence reports concerning Cuba. Mrs. Myers' preferred method of passing the documents involved exchanging shopping carts with Cuban operatives at the grocery store.

The FBI said they communicated with their Cuban handlers using a short-wave radio kept in their apartment.

The Myers ultimately were uncovered as spies as the result of an undercover FBI operation that began last month, according to authorities.

The FBI said an agent posing as a Cuban operative approached Mr. Myers outside the Johns Hopkins School of Advanced International Studies, on Massachusetts Avenue in the District, and said he was "instructed" to make contact. Before leaving, according to the FBI, the undercover agent gave Mr. Myers a cigar and congratulated him on his birthday.

Mr. Myers taught Western European studies part-time at the Johns Hopkins school, which is also where he earned his doctoral degree.

The FBI said the Myerses gave up details of their spying during subsequent meetings with the undercover agent.

"We remain vigilant in protecting our nation's secrets and in bringing to justice those who compromise them," said David Kris, assistant attorney general for national security.

• Nicholas Kralev contributed to this report.