BOTH during and after the Cold War, the US has had a long history with spies and double agents, many lying right under the nose of the authorities.

Robert Philip Hanssen – double agent working for the FBI but spying for the Russians from 1979 to 2001. Hanssen was arrested making a 'drop' of valuable information to his Soviet handlers at a park in Virginia.

The spy sold "highly classified" national security secrets for $1.4m in cash and diamonds. He is serving a life sentence in a maximum security prison.

FBI director Louis J Freeh said of the arrest: "This kind of criminal conduct represents the most traitorous action imaginable… It also strikes at the heart of everything the FBI represents."

Walter Myers (and his wife Gwendolyn) – arrested by the FBI in 2009 on suspicion of spying for Cuba for three decades. Myers, a descendant of Alexander Graham Bell, worked for the US state department for 20 years and was also an academic.

His spying career, made possible by his position at the Department of Justice's Bureau of Intelligence and Research, included clandestine supermarket meetings in which top-secret documents were exchanged in shopping trolleys.

When caught, in his 70s, Myers received life in prison; Gwendolyn got seven years.

Tai Shen Kuo – a former furniture salesman, he received a 16-year prison term (later redued to five) for leading a 'spy ring' that helped China obtain US military information by cultivating a relationship with Pentagon weapons analyst Gregg Bergersen.

During a rendezvous taped by the FBI, Bergersen pleaded with Kuo not to tell anyone he was the source of the information, including details of American arms sales to Taiwan.

"I'd get fired for sure on that," he said. "Well, not even get fired; go to [expletive] jail."

Ben-ami Kadish – avoided jail but was fined $50,000 (€40,000) last year after being found to be providing leaked US military documents to an Israeli agent in the early 1980s.

However, following the arrest of the 85-year-old, there was further mystery as to how his case was handled by the authorities when he was permitted to plead guilty to just one charge of conspiracy to act as an unregistered agent of Israel.

Critical of the handling of the case, judge William Pauley III said: "This offence is a grave one that implicates the national security of the United States. Why it took the government 23 years to charge Mr Kadish is shrouded in mystery."