- Video report by ITV News reporter Olivia Kingsley
The Home Secretary has said the couple exposed to the nerve agent Novichok in Amesbury were exposed in an area that hadn't been part of the clean-up following the Skripal's poisoning months before.
But Sajid Javid also told the Commons he "cannot rule out" the possibility the Russian-created Novichok found in Amesbury was from the same batch used in the Salisbury attack.
Over 100 Counter Terrorism Network police officers are investigating the incident and it has been revealed the couple were "exposed to the nerve agent after handling a contaminated item".
The Metropolitan Police say detectives are "working as quickly and as diligently as possible to identify the source of the contamination".
The Kremlin, accused of being behind the March attack in Salisbury, says it has so far received no "appeal" from the UK in relation to the Amesbury incident and branded the recent poisoning "disturbing".
Speaking in the Commons, Sajid Javid told MPs: "What we are absolutely clear on from Porton Down is that this is the exact same nerve agent from the Novichok family of nerve agents, but the same type of nerve agent from that family that was used in the March attack.
"We cannot attribute this to the same batch at this point and scientists will be looking into that, I'm also told that may not even be possible because of a number factors, but we cannot rule out, of course, that it was from the same batch."
He added: "We have taken a very robust approach to decontamination and there is no evidence that either the man or the woman in hospital visited any of the places that were visited by the Skripals.
"Our strong working assumption is that the couple came into contact with the nerve agent in a different location to the sites which have been part of the original clean-up operation."
A man and woman, named locally as Dawn Sturgess and Charlie Rowley, were taken ill on Saturday in Amesbury, around eight miles from where the Skripals were poisoned in March.
Kremlin spokesman Dmitry Peskov said: "This is very disturbing news. Of course, it triggers profound concern in connection with the similar incidents in the UK.
He added: "We wish them a speedy recovery."
The Russian Embassy in London has called for a joint investigation into the poisoning, reiterating its response to the Salisbury incident.
Baptist minister Reverend Roy Collins has told ITV News that he cared for an "incoherent" Mr Rowley when he attended a family fun day at Amesbury Baptist Church in Wiltshire on Saturday.
"Charlie was there and he did stand out a little bit, he was not very well dressed and was rather disheveled in his appearance.
"I assumed that he had been drinking, so I wanted to get some food into him and he did take something - we had an opportunity to have a very brief chat," he added.
One theory understood to be under investigation is that the pair may have inadvertently found a container - such as a phial or syringe - used to transport the nerve agent for the initial attack and discarded in a public place.
Novichok remains highly toxic for a considerable period of time, so even the tiniest trace remaining in a container picked up by the victims could account for their severe illness.
On Friday, the day before they became ill, the couple - who are both in their 40s - were in Queen Elizabeth Gardens in nearby Salisbury, close to where the Skripals were found.
Wiltshire Police initially thought the couple had taken contaminated crack cocaine or heroin when they were found at Mr Rowley's flat in Muggleton Road in Amesbury on Saturday, but due to symptoms the pair were displaying, samples were taken from them and sent to the Government chemical weapons research laboratory at Porton Down for testing.
A major incident was then declared.
Assistant Commissioner Neil Basu said it is not thought that the individuals are linked in any way to Russia or to the Skripals.
Images obtained by ITV News show a man being stretchered into an ambulance from a house in Amesbury on Saturday.
The patient in the video is surrounded by police and paramedics wearing protective suits and face masks as they load him onto the ambulance.
No one else is believed to have been taken ill, including any of Mr Rowley and Ms Sturgess' friends who visited the park with them on Friday.
However, Professor Dame Sally Davies, Chief Public Health Officer for England, advised anyone who has been to any of the areas which are now cordoned off to wash the clothes they were wearing, and wipe any items, bags or shoes they had with them, with wet wipes.
Dame Sally continued that her advice was "highly precautionary", while Mr Javid said in a separate statement that "the risk to the general public is low"
Chemical weapons expert Hamish de Bretton-Gordon said he believed Mr Rowley and Ms Sturgess were "incredibly unlucky, it must be a million-to-one chance.
"There might will be the odd molecule of Novichok left around from the Salisbury attack, but the areas where it's previously been discovered have been decontaminated or are being decontaminated, so the fact that a couple of molecules have infected these two people is bizarre."
In June and following a multi-million pound decontamination operation on sites in the city which it was feared could have come into contact with Novichok, Prince Charles and the Duchess of Cornwall visited Salisbury to show it was safe and open for business.
Following the attack on the Skripals, businesses close to the scene suffered from a fall in customer visits by as much as 80%, while across Salisbury, tourism was down by 15%.
A friend of Mr Rowley and Ms Sturgess, Sam Hobson, told ITV News that he called an ambulance after Mr Rowley began foaming at the mouth on Saturday, but added that none of the other people - aside from Ms Sturgess - who were with the couple at Queen Elizabeth Gardens in Salisbury on Friday, had been taken ill.
He continued: "It's obviously something that they touched [that has made the pair ill] and they've got infected by it so they're getting enzymes pumped through them in the hospital, same as the other people did last time."
It is believed that one of the last places Mr Rowley and Ms Sturgess were seen in public was a family fun day at Amesbury Baptist Centre on Saturday afternoon.
The church is one of at least five locations in Amesbury and Salisbury which has been cordoned off by police.
Church secretary Roy Collins said: “Last weekend we held a community fundraiser and we understand this may well be the last event this couple went to in public.
“We are all quite puzzled and shocked – naturally the connection with Salisbury and recent events there mean there is a heightened public interest.
“We are praying for the couple. One of our members knows them and clearly there are concerns for them and any others in the community.
“They are not church members or regulars.”
Mr Collins said around 200 people attended the event, including many families and children, but “nobody else has suffered any ill-effects”.
The address where the couple were found is on a new housing development on the southern edge of the town, which lies close to Stonehenge.
Sergei Skripal, 67, and his 33-year-old daughter Yulia were left in a critical condition after they were found slumped on a bench in Salisbury city centre on March 4.
They spent weeks in Salisbury District Hospital, where they underwent treatment for suspected exposure to the Russian-created nerve agent Novichok.
The British Government has accused Russia of being behind the attack on Mr Skripal, who settled in the UK after a spy swap.