Russian spy and his daughter collapsed. - They are critically ill from an unknown substance. Russian spy: Sergei Skripal collapsed alongside daughter Yulia Skripal, in her 30s, and father Sergei, 66, are critically ill in hospital after being found unconscious in Salisbury, Wiltshire, on Sunday. UK police are trying to find out what "unknown substance" harmed the pair. Former agent Mr Skripal, whose wife, son and older brother have all died in the past two years, was granted refuge in the UK following a "spy swap" in 2010.