Transcript for Ex-Russian spy critical due to 'unknown substance'

This sleepy quiet town in rural England became the center of global attention yesterday. Author to manage a couple who mysteriously taken M on Sunday was a former Russian spy and distorts. Members of the public contacted police office but the couple have cost out in the public. Well behind me is the band's web and former Russian spice arrogance could on his door to you via reportedly lost consciousness on Sunday often. This anti pot is not in cordoned off and forensics and analyzing the scene they on now in critical condition in a nearby hospital. Police say they came in contact with an unnamed substance second street was sentenced to freeze and in 2006 by the Russian state the passing secrets to British intelligence. He then sought refuge in the UK off giving positive following a prisoner exchange with the US in 2010. With the former Russian spy and the presence of possible harmful substance. Comparisons being made with the poisoning of ex FSB officer out eggs on them that they yank. He was knighted in 2006 off the pissed he was spite with a radioactive uranium. The British found the Russian state to be responsible. Speaking today the foreign secretary issued a stark warning indeed but somehow people. I seek to governments around the world. The new attempt to take innocent life on UK so who do are the unsanctioned. Pool unpunished. The question now is what was the unnamed substance that has left spring pollen has sort of fighting for them lives. And is this once again a case of Russian retribution against double agents. Dynamic violent ABC news and Salisbury and.

This transcript has been automatically generated and may not be 100% accurate.