Charlie Rowley, 45, and Dawn Sturgess, 44, were found unconscious at a house in Muggleton Road, Amesbury, Wiltshire, on June 30, the BBC reported.
They remain in critical condition.
There was "nothing in their background" to suggest the two were targeted, the Met Police said.
Met Police Assistant Commissioner Neil Basu said it could not be confirmed whether the nerve agent came from the same batch that Skripal and his daughter Yulia were exposed to.
But he said the possibility was "clearly a line of enquiry".
Basu said no contaminated items had yet been found, but officers were putting together a "very detailed examination of the couple's movements" in order to determine where they were poisoned.
He added that members of the public should not pick anything up if they don't know what it is. "We have no idea what may have contained the nerve agent at this time," he said.
Amesbury is about 10 miles from Salisbury, where Skripal and Yulia were poisoned with Novichok, a suspected military nerve agent, in March.
England's chief medical officer, Sally Davies, said: "I want to reassure the public that the risk to the general public remains low."
As a precautionary measure, sites in Amesbury and Salisbury, believed to have been visited by the couple before they fell ill, have been cordoned off, including a church, park and a chemist.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
