Media playback is unsupported on your device Media caption Russian spy attack: What we know so far

A man who is critically ill after being exposed to an unknown substance in Wiltshire is a Russian national convicted of spying for Britain, the BBC understands. See more: Boris Johnson promises to 'bring Russia to heel' following the alleged poisoning of Sergei Skripal

2:11 p.m. — The UK's national counterterrorism police say they are leading the investigation into the suspected poisoning. "The two people -- a man aged in his 60s, and a woman aged in her 30s -- were found unconscious on a bench in The Maltings in Salisbury," Wiltshire police said on Monday, adding that the injured are known to each other. Temporary Assistant Chief Constable Craig Holden said: “The pair, who we believe are known to each other, did not have any visible injuries and were taken to Salisbury District Hospital. The former colonel in the Russian military intelligence, who was sentenced to 13 years in prison in 2006, was among four other convicts who were given pardons and one of two sent to Britain in 2010 in a deal that was said at the time to be the largest spy swap since the Cold War. It quoted Russia's Federal Security Service (FSB) as saying Skripal, a former Russian military intelligence colonel, was convicted for "treason in the form of espionage" and that he had been recruited by Britain's MI6 intelligence service, following his arrest in December 2004. Skripal was granted asylum in Britain after being pardoned by Russia in a 2010 “spy swap” deal with the US, under which 10 Russian spies arrested by the FBI were released. The pair are currently in intensive care at Salisbury Hospital under supervision of experts from Public Health England's Centre for Radiation, Chemical and Environmental Hazards. "He was doing some strange hand movements, looking up to the sky...

"They looked so out of it I thought even if I did step in I wasn't sure how I could help."
Former Secret Intelligence Service (MI6) spy Sergei Skripal and his daughter are taken to a hospital in critical condition after being exposed to an unknown substance in Wiltshire, United Kingdom. Skripal was granted refugee status in the UK following a "spy swap" deal between the UK and Russia in 2010.