ABC News July 5, 2018

Couple sickened with nerve agent not 'deliberately targeted,' deepening mystery

WATCH: Couple in UK exposed to same poison as ex-spy

A couple who has fallen critically ill in England is at the center of a widening investigation into whether they were exposed to a Soviet-era nerve agent that previously sickened a former Russian spy and his daughter in a nearby town.

Sergei Skripal and his daughter, Yulia, were poisoned with the nerve agent Novichok in Salisbury in the spring, according to the British government. Several miles away in the town of Amesbury, a British pair is being treated after being exposed to the same nerve agent on Saturday.

Geoff Caddick/AFP via Getty Images
Police officers are seen outside Amesbury Baptist Centre in Amesbury, nine miles north of Salisbury, southern England, on July 4, 2018.

Meanwhile, the British government has convened an emergency committee in the Cabinet War rooms in Westminster to discuss the developments.

After the meeting, Home Secretary Sajid Javid said the main line of inquiry into the current investigation is whether there is any link to the Skripals incident. In a televised statement in the House of Commons, he added that the latest couple is thought to have been exposed to the nerve agent at a location not previously associated with the Skripals incident.

AFP/Getty Images
A still image taken from video footage recorded on June 30, 2018, and released on July 5, 2018, shows a man on a stretcher being put into an ambulance by medics and police outside a residential address in Amesbury, southern England, on June 30, 2018.

Prime Minister Theresa May, meeting with German Chancellor Angela Merkel, said her thoughts are with the people of Wiltshire. “To see two more people exposed to Novichok in the U.K. is obviously deeply disturbing and the police, I know, will be leaving no stone unturned in their investigation in relation to what has happened,” she said.

AFP/Getty Images
A still image taken from video footage recorded on June 30, 2018, and released on July 5, 2018, shows a man on a stretcher being put into an ambulance by medics and police outside a residential address in Amesbury, southern England, on June 30, 2018.

The couple, whose identities have not been released but whom the Associated Press has identified as Dawn Sturgess and Charlie Rowley, is in critical condition at Salisbury District Hospital. That's where the Skirpals received successful treatment and were discharged in April.

AP/Polaris
Sergei Skripal, a former colonel of Russia's GRU military intelligence service, looks on inside the defendants' cage as he attends a hearing at the Moscow military district court on Aug. 9, 2006.| Daughter of former Russian Spy Sergei Skripal, Yulia Skripal is seen in this undated photo.

The pair sickened over the weekend are not believed to have been “deliberately targeted,” according to the Metropolitan Police.

(MORE: Scotland Yard confirms 2 people were exposed to a nerve agent in Amesbury ) (MORE: Chemical weapons watchdog backs UK findings on nerve agent used in Salisbury attack ) (MORE: Ex-spy attacked with nerve agent discharged from UK hospital )

Dozens of officers from counterterrorism command, as well as experts from the military research center of Porton Down, also located in Wiltshire and helping with the investigation.

On Saturday, emergency services were called to the same house in Muggleton Road in Amesbury on two separate occasions. They first responded to a woman, 44, who had lost consciousness, and later in the day to a man, 45, who began exhibiting strange behavior, a friend who was with him told authorities.

Francois Duckett/AP
Local police declared the recent poisoning a "major incident," four days after a couple was found at a residential building in Amesbury, eight miles from Salisbury.

Muscle spasms, slurred speech and the loss of muscle control are symptoms consistent with what the Skirpals exhibited when they were found slumped on a park bench in March. Initially, police believed they were dealing with a case of contaminated drugs, possibly heroin or crack cocaine.

Jack Taylor/Getty Images
Police officers stand at a cordon around an area of grass near to Amesbury Baptist Centre as Wiltshire Police declare a major incident after a man and woman were exposed to an unknown substance, July 4, 2018, in Amesbury, England.

But on Wednesday, Wiltshire Police announced a "major incident," with analysis of samples being confirmed as Novichok by Porton Down later in the day.

British officials have blamed the Russians for the March 4 poisoning of Sergei and Yulia Skripal.

Jack Taylor/Getty Images
Police on the scene at Muggleton Road where a major incident was declared after a man and woman were exposed to an unknown substance on July 4, 2018, in Amesbury, England.

But Russia has fiercely denied the allegations. On Thursday, President Vladimir Putin’s spokesman Dmitry Peskov again reiterated the Kremlin’s dismissal of the British accusations.

“The British side has never presented any compelling evidence to support the baseless allegations of Russia's involvement,” he said.