Russia and the United States appeared on Thursday to be considering a spy swap to send home a ring of suspected Russian agents in exchange for people convicted in Russia for passing secrets to Western governments.
A Russian nuclear expert jailed for passing secrets to the West told his family this week that he had been informed by Russian officials that he was to be handed over as part of the spy swap.
He said he had seen a list of at least 10 names who would be exchanged for the 10 suspected Russian agents who were arrested last month in the United States.
The following are details about four Russians who have been mentioned as possible candidates for the swap:
A nuclear expert and former research fellow at the Moscow-based Institute for U.S. and Canadian Studies, Sutyagin was sentenced to 15 years in jail in 2004.
He was charged with passing classified military information to a British firm which prosecutors said was a front for the U.S. Central Intelligence Agency. He has always said he was innocent.
His lawyer, Anna Stavitskaya, and family say he was told by Russian officials that he would be swapped for one of the suspected agents in the United States.
Under the swap plans, Sutyagin would be sent to Vienna and then London. He was being held in Moscow's high security Lefortovo prison earlier this week.
Skripal, a former colonel of Russia's military intelligence, known as GRU, was convicted in 2006 on charges of espionage for Britain's MI6 intelligence agency. He is currently serving a 13-year prison term.
At the time of his conviction, Russian media said he had exposed dozens of Russian intelligence officers operating for Britain's MI6.
Sutyagin told his family that he had seen a list of at least 10 people who would be swapped for the agents in the United States and that Skripal's name was on the list.
Former colonel in Russia's Foreign Intelligence Service known as the SVR, Zaporozhsky was convicted in 2003 and sentenced to 18 years in prison on charges of treason.
At the time, Russian media speculated that Zaporozhsky had been behind the exposure of former FBI agent Robert Hanssen and ex-CIA officer Aldrich Ames, both convicted on charges of spying for Russia.
Upon retirement in 1997, Zaporozhsky moved to the United States, where he was suspected to have shared classified information with intelligence agencies there. He was arrested upon returning to Russia in 2001.
Russia's Kommersant newspaper cited an unidentified Russian intelligence source as saying that Zaporozhsky and Alexander Sypachev might also be swapped.
Convicted on charges of espionage, Sypachev was a colonel at Russia's Foreign Intelligence Service at the time of his arrest in 2002. He was handed an eight-year prison term.
He was suspected of contacting the U.S. embassy in Moscow with offers of classified information. He was later detained by the FSB security service, the successor of the KGB, during an attempt to hand over data.
(Reporting by Alexei Anishchuk; Editing by Amie Ferris-Rotman and Diana Abdallah)
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