British PM Theresa May announces measures against Russia, who continue to deny involvement with the poisoning of a former double agent and his daughter.
The policeman who rushed to help poisoned Russian spy Sergei Skripal and his daughter said his life will "never be the same" as he was released from hospital.
Detective Sergeant Nick Bailey said he was now having to concentrate on rebuilding his life after suffering from the effects of the deadly nerve agent used to target Col Skripal, 66, and Yulia, 33, in Salisbury.
The development came as a High Court judge gave doctors permission to take blood samples from the pair while they are still alive so that tests can be carried out by chemical weapons experts.
Det Sgt Nick Bailey has been released from hospital.
The Skripals may have suffered permanent brain damage and their condition could "rapidly deteriorate," tests have shown.
As Bailey returned home following his ordeal, he said in a statement: "I recognise that 'normal' life for me will probably never be the same- and Sarah and I now need to focus on finding a new normal for us and for our children."
He added: "I have spent all my time since the incident really focusing on trying to get better and trying not to think about anything else.
"I want people to focus on the investigation- not the police officer who was unfortunate enough to be caught up in it. All I have done is represent every police officer who goes out there every day and puts their life at risk."
But DS Bailey's wife Sarah described her husband as a hero.
She said: "Nick doesn't like the term hero, but he has always been a hero to me and our children."
Bailey, who said she and her husband had been overwhelmed by messages of support from the public and the wider "police family", added: "This has quite simply been the most traumatic event of our life and it feels like our world has been turned upside down in a really short space of time."
DS Bailey will continue to receive intensive occupational therapy and occupational psychotherapy while his wife and their two young children are receiving specialist support to help them overcome the "horror" of seeing their father injured in the line of duty, it emerged.
The couple spoke through Wiltshire's temporary chief Constable Kier Pritchard after reports emerged that a second police officer investigating the nerve agent attack is receiving treatment for suspected poisoning.
A vehicle wrapped in blue tarpaulin is removed from Larkhill Rd in Durrington, 16 kilometres north of Salisbury, as investigations into the nerve agent attack continue. Photo / AP
The uniformed constable is understood to have developed minor symptoms, including skin irritation, and is receiving treatment as an outpatient at Salisbury District Hospital.
He is reported to have come into contact with an object that possibly had 'secondary contamination from the nerve agent used to target the Skripals nearly three weeks ago.
Meanwhile, Mr Justice Williams heard details about the case at a private Court of Protection hearing in London, after which he gave permission for blood samples to be taken from the Skripals to enable international chemical weapons experts to carry out crucial tests.
In a detailed judgment, he said the pair lacked the mental capacity to give permission and revealed that they remain in a critical condition under heavy sedation and may never recover from the nerve agent attack.
He said Col Skripal was unable to communicate at all, while his daughter could not communicate "in any meaningful way."
Not a single relative has sought information from the hospital about their condition since they were admitted almost three weeks ago, the court heard, meaning that the judge was unable to consult them about his decision.
"The evidence is that samples taken from living individuals are of more scientific value than post mortem samples," he said.
"The precise effect of their exposure on their long term health remains unclear, albeit medical tests indicate that their mental capacity might be compromised to an unknown and so far unascertained degree.
"At present both Mr and Ms Skripal are critical but stable; it is not inconceivable that their condition could rapidly deteriorate."
He said it was not possible to say whether the "current lack of capacity" was temporary or permanent.
"On balance the lack of capacity arises from an impairment or disturbance of the brain arising out of both sedation and the impact of the exposure to a nerve agent," he added.
Sergei Skripal, caught on CCTV camera in the days before the attack.
The judge heard evidence from five witnesses, from Porton Down scientists to senior Foreign Office and Home Office officials who addressed "sensitive" issues.
He heard that security measures were in place at Salisbury District Hospital, where they are both in intensive care, "to ensure their physical safety."
The judge had to make his decision in the absence of information about the beliefs and values of the Skripals but noted that most people had an "acute" sense of justice would want to "truth spoken to power" when a serious crime had been alleged so that "no-one whether an individual or a State is above or beyond the reach of the law".
"An individual subjected to such an attack with personally catastrophic consequences would want to see it fully and properly investigated and that all appropriate steps to identify the perpetrators (individual and state) have been taken so that they can be held to account," he said.
The judge concluded that the OPCW's investigation may provide information on how to treat Skripal and his daughter and what happened to them.
Inspectors arrived in the UK earlier this week and will now collect fresh blood samples from the Skripals in order to conduct their own analysis about the use of nerve agents and confirm the results of tests already undertaken by UK experts from Porton Down.
Yesterday, they visited Col Skripal's home, which has been cordoned off by police since the attack, and took swabs from door handles inside and outside the house, along with swabs from a keyboard and other objects.
They have also visited the Mill pub, where the Skripals enjoyed a drink shortly before they collapsed, and the Porton Down chemical weapons research centre to take samples of the nerve agent gathered by police from locations in Salisbury in order to carry out their own analysis.
Detectives are trying to established whether the nerve agent which left the Skripals fighting for their lives was inserted into Col Skripal's car or unwittingly brought from Russia to Britain by Yulia in her suitcase, possibly secreted in a present or item of clothing.
The Russian government has been blamed for the attack on the former Military Intelligence Officer turned MI6 agent, who was exchanged in a spy swap and moved to Britain in 2010.
Detectives are trying to established whether the nerve agent which left the Skripals fighting for their lives was inserted into Col Skripal's car or unwittingly brought from Russia to Britain by Yulia in her suitcase, possibly secreted in a present or item of clothing.
