Dawn Sturgess and Charlie Rowley.
Counter terror police investigating the Novichok murder of a mother-of-three, have said they can cannot offer public safety guarantees, as it was revealed the second victim could have just days to live.
Dawn Sturgess died yesterday, nine days after receiving a large dose of the deadly nerve agent, when she picked up a container that had likely been used in the assassination attempt on Russian double agent Sergei Skripal in March.
Her mother said the 44-year-old, who had alcohol and addiction problems, had suffered heart failure after more than a week in intensive care.
Her boyfriend, Charlie Rowley, 45, is on life support in Salisbury District Hospital, but is not expected to make a full recovery.
It comes as detectives leading the hunt revealed a car has been removed from an address 50km away in Swindon in relation to the ongoing probe.
A Wiltshire Police spokesman: "We have arranged the transportation of a car from an address in Swindon this evening in relation to the on-going incident in Amesbury. The public should not be alarmed by this. Those involved have the training and expertise to safely remove the vehicle."
Detectives are desperately trying to locate the source of the contamination - which is believed to be a glass container or syringe - which had lain undetected in Salisbury since the Skripal poisoning in March.
Speaking outside Scotland Yard, Assistant Commissioner Specialist Operations Neil Basu said: "In the four months since the Skripals and [Detective Sergeant] Nick Bailey were poisoned, no other people besides Dawn and Charlie have presented with symptoms.
"Their reaction was so severe, it resulted in Dawn's death and Charlie being critically ill. This means that they must have got a high dose and our hypothesis is that they must have handled a container we are now seeking."
But he said he could not reassure the public in Salisbury that there was no risk to their safety.
'Couple must have handled a container which contained a very strong dose of novichok' say counter-terror police who are still trying to locate the contaminated container
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He said: "We continue to work extremely closely with public health and scientific experts to continually monitor and assess the ongoing levels of risk to the public as the investigation progresses.
"Whilst I simply can't offer guarantees, last night Public Health England emphasised that the risk to the general public at this time remains low."
A total of 21 people, including eight police officers, nine healthcare workers and a paramedic, have sought medical, since last week, but all have been given the all clear.
Police also gave more details of the movements of the couple in the hours after they were poisoned, including revealing they have been examining a local bus and red Ford Transit Van they travelled in.
After spending the afternoon of June 29 shopping and relaxing in Salisbury, Sturgess and Rowley visited her home in John Baker House, before travelling by bus back to his flat 12km away in Amesbury.
A police spokesman said the bus had been seized by Wiltshire Police and examined at the Government's defence laboratory at Porton Down before being given the all clear.
On June 30, after Sturgess was taken ill, Rowley travelled in a red Ford Transit van with three other people.
Basu said the vehicle had also been taken to Porton Down for further tests as a precautionary measure.
He said: "Three other men, who were also in the van that day, have been identified and contacted by police. None of them are showing any signs of having been exposed to the nerve agent or feeling unwell, and are being screened as a precaution. "
The van was taken away from an address in Amesbury, close to where Rowley lived, by military personnel from the Royal Air Force.