A MAN who is critically ill in hospital after being exposed to an unknown substance in Salisbury is a Russian convicted of spying for Britain.

The man who collapsed in the Maltings last night was Sergei Skripal, a 66-year-old Russian national granted refuge in the UK following a spy swap between the US and Russia in 2010.

Salisbury Journal:

Police declared a major incident after a man in his 60s and a woman in her 30s were found unconscious on a bench in the shopping centre on Sunday.

Emergency services at the scene suspected the substance may have been a powerful drug called fentanyl, but nothing has yet been confirmed.

They were taken to Salisbury District Hospital where they are in a critical condition in intensive care.

This morning the A&E department was closed while firefighters decontaminated the area.

Salisbury Journal:

Police arrived at Skripal's home in Christie Miller Road, Salisbury, yesterday at 5pm, according to neighbours.

The electoral register shows he has lived there since 2013.

At the time of the spy swap The Guardian reported that Sergei Skripal and Igor Sutyagin were traded, along with two other Russians, for ten deep cover "sleeper" agents planted by Moscow in the US.

Britain and the US had claimed the four agents released by Moscow were “more serious” individuals than those they had been swapped for.

One reason Skripal may still be regarded as a “target” would be that as a former Russian army colonel he was convicted of passing the identities of Russian agents working undercover in Europe to MI6.

He was sentenced in August 2006 to 13 years in jail for spying for Britain. 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.

His reward for staying in Britain was said to have been the gift of a home and pension.

According to the Land Registry his home is a semi-detached four-bedroom property that was last sold in August 2011 for £260,000.