Two Britons critical after exposure to nerve agent used on Russian spy

Police said there was no evidence to suggest that the man and the woman, named locally as Charlie Rowley and Dawn Sturgess, "were targeted in any way"

A British couple left critically ill in an English village were exposed to Novichok -- the same nerve agent used in the poisoning of a former Russian spy and his daughter in the nearby city of Salisbury this year, police said today.

Counter-terrorism police are now leading the investigation into the incident after tests at the Porton Down defence laboratory confirmed the nature of the substance, which Britain says is a Soviet-made military grade nerve agent.

"It's the same nerve agent. Whether we can ever tell if it's the same batch will be up to scientists to determine," Neil Basu, head of counter-terrorism police, told reporters.

"The priority for the investigation team now, is to establish how these two people have come into contact with this nerve agent," he said.

Basu said there was no evidence to suggest that the man and the woman, named locally as Charlie Rowley and Dawn Sturgess, "were targeted in any way".

The two fell ill on Saturday in Amesbury in southwestern England, close to where former double agent Sergei Skripal and his daughter Yulia collapsed on a bench on March 4 in an incident that sparked a bitter diplomatic crisis with Russia.

"The possibility that these two investigations might be linked is clearly a line of enquiry for us," Basu said.