With Skripal critically ill in Salisbury, here is a summary of what is known about him

A former Russian army colonel convicted of passing the identities of Moscow agents working undercover in Europe to MI6 in 2006, Sergei Skripal arrived in the UK as part of a high-profile spy swap in 2010.

Skripal was sentenced to 13 years in jail for spying for Britain in Russia in August 2006 after being convicted of “high treason in the form of espionage”.

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Russian prosecutors said he had been paid $100,000 by MI6 for information, which he had been supplying since the 1990s when he was a serving officer. The FSB, Russia’s security agency, said the information passed to MI6 by Skripal constituted state secrets.

Skripal served in Russia’s GRU military intelligence until 1999, reaching the rank of colonel. He then worked at the Russian foreign ministry’s office in Moscow until 2003, when he went into business.

“You outplayed me,” Skripal reportedly told FSB agents after his arrest. An FSB spokesperson compared Skripal to Colonel Oleg Penkovsky, who was executed by the Soviet Union in 1963 for supplying the United States with information during the Cuban missile crisis.



In July 2010, the then Russian president, Dmitry Medvedev, pardoned Skripal and the former colonel was one of four spies exchanged for 10 deep cover “sleeper” agents planted in the US by Moscow.

He and another Russian were flown to the UK after the exchange and were debriefed by MI5 and MI6 officers. At the time, Skripal was considered the more important of the two spies brought to Britain. It was assumed that Skripal had since been given a new identity, a home and a pension.

The two Russians who went to the US were Alexander Zaporozhsky, a KGB colonel whose information unmasked traitors inside the CIA and FBI, and Gennady Vasilenko, a former KGB officer.

Among the 10 Russian spies deported from the US was Anna Chapman, who was arrested at a New York police department precinct after turning in a fake passport an undercover FBI agent had given to her. The daughter of a Russian diplomat, she became the most recognisable of the 10 agents after her former husband sold photographs to the press showcasing her social life and travels.

Before settling in the US, she had lived in the UK for seven years after marrying an Englishman. Prosecutors say Chapman used a specially configured laptop computer to transmit messages to an unnamed Russian official.