A British couple left critically ill in a village close to where a former Russian spy and his daughter were poisoned earlier this year were exposed to the same nerve agent, British police said on Wednesday.
The couple, believed to be Charlie Rowley and Dawn Sturgess, were found unconscious at a house on Saturday. No one else has reported to the hospital with the same symptoms.
"This evening we have received test results from Porton Down that show the two people have been exposed to the nerve agent Novichok," Neil Basu, head of counter-terrorism, said in a statement.
The Porton Down defence laboratory also confirmed the use of Novichok, which it said was made in the Soviet Union, in the case of Sergei and Yulia Skripal.
Basu said there was "no evidence" to suggest that the man and the woman "were targeted in any way".
"It's the same nerve agent. Whether we can ever tell if it's the same batch will be up to scientists to determine," Basu said, adding that police had not been able to establish the transmission mechanism.
"This remains a low risk to the general public. We're satisfied that if anyone was exposed to that level of nerve agent by now they would be showing symptoms," he said.
Basu said that counter-terrorism police were now leading the investigation, as they did in the case of the Skripals.
He said 100 detectives were working on the case.
Both the man and the woman were taken ill on Saturday.
Basu said the 44-year-old woman collapsed first and an ambulance was called to a house in Amesbury in southwestern England near the city of Salisbury.
The same day, the ambulance service was called back to the same address where a man had fallen ill.
"At this stage no-one else has presented with the same symptoms linked to this incident," Basu said.
Basu said that there was "no evidence that either the man or woman recently visited any of the sites that were decontaminated following the attempted murders of Sergei and Yulia Skripal".
