BRIDGE 2

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.

Sergei Skripal, 66, was granted refuge in the UK following a "spy swap" between the US and Russia in 2010.

This is UK version of Stanislav Lunev, dig deep'

http:// www.bbc.co.uk/news/uk-43295134