By Jon Donnison
BBC News, Washington
Walter Kendall Myers had access to sensitive information.
The story of Walter Kendall Myers and his wife Gwendolyn reads like a John Le Carre novel, perhaps crossed with a Miss Marple whodunnit.
A glamorous story of spying, deception and coded messages between Washington and Havana.
But also with a touch of mundane domesticity about it, with secret meetings held in supermarkets with classified documents exchanged in shopping trolleys! Can this really have been a safe way to carry out grand espionage?
If the US Department of Justice is to be believed, for over three decades this American couple, now in their seventies, were spying for the Cuban government.
The allegations are that from his position at the state department's Bureau of Intelligence and Research (INR), Mr Myers was able to access top secret documents and pass them to his handlers from the Cuban Intelligence Service.
'Top secret' clearance
According to court documents filed in Washington, Mr Myers was first approached by the Cuban government in 1978, and he and his wife, a banking analyst, agreed shortly afterwards to provide information to Cuban intelligence.
He was known as agent 202, possibly after the Washington DC telephone area code. She was agent 123.
Mr Myers first began working for the US state department in 1977 as an instructor at the Foreign Service Institute, where he was given "top secret" security clearance.
In 1999, he was granted an even higher security clearance when he joined the INR on a permanent basis.
Such clearance gave him access to top sensitive information at the heart of the US government. In one year alone the Justice Department says he used his computer to view about 200 sensitive or classified documents relating to Cuba.
Mr Myers allegedly received his instructions from his Cuban handlers over short wave in the form of coded messages. Bizarrely, prosecutors say he would then meet them in grocery stores and supermarkets exchanging top secret files by swapping trolleys.
It seems whatever they were passing off in those trolleys went to the highest level. They even allegedly met Cuban leader Fidel Castro himself in 1995.
Plans to escape
Mr and Mrs Myers were eventually rumbled after an undercover sting operation. An FBI agent posing as a Cuban intelligence officer approached Mr Myers, telling him that he had been sent by the Cuban government to obtain information from him.
During a subsequent meeting, Mr Myers and his wife agreed to provide information about US government personnel to the undercover agent, and made statements about their past activities for the Cuban government, the Justice Department alleges.
They apparently told the undercover agent that they had been making plans to one day escape to Cuba travelling by boat. Mr Myers said he studied shipping charts and maps.
Their motives are not really clear but they seemed to have a dislike of their fellow Americans.
When the undercover agent asked them whether they thought the US government would ever lift the travel ban on Cuba, Mr Myers allegedly said: "Believe me, those North Americans, you don't want them
.the trouble with this country is there are just too many North Americans."
More information will no doubt come out if and when the case goes to court.
Despite the fascinating details of this case, it is really a major embarrassment to the US government that two people could be operating undetected for so long.
Mr and Mrs Myers, who are also charged with wire fraud, could face up to 35 years in prison.