The mysterious deaths of up to four Russians or people with links to Moscow could be reinvestigated after a former double agent and his daughter were poisoned, the Home Secretary has said.
The poisoning of ex-spy Sergei Skripal, 66, and his daughter Yulia, 33, has cast a new light on more than a dozen allegedly suspicious cases linked to Russia.
Former Met Police commissioner Lord Blair and Yvette Cooper, Labour chairwoman of the Commons Home Affairs Committee, have called for a fresh police investigation into 14 deaths in the UK.
Amber Rudd has said there was no new evidence in those cases, but some could be looked at again following the probe into the attempted murder of the Skripals.
Moscow has been given a midnight deadline after Prime Minister Theresa May said it was "highly likely" that Russia was responsible for the March 4 attack in Salisbury, Wiltshire.
Mrs May said the Skripals were poisoned by a substance that was part of the Novichok group of nerve agents which were developed by the Soviet military during the 1970s and 1980s.
President Vladimir Putin's government has denied the allegations and said it has requested access to samples of the nerve agent.
There have been calls for police to take another look at 14 allegedly suspicious deaths in Britain after BuzzFeed reported they had been linked to Russia by US spies.
Ms Rudd told the Evening Standard that there was no new evidence, but added: “Look, you know I’m not dismissing it at all and after we’ve got beyond this incident it may be right to look at them all again.
“Well, not all of them - I expect even Lord Blair would probably say one or two or three or four.”
Last week, Lord Blair told BBC Radio 4's Today programme: "I am certainly of a view that this extraordinary attack in Salisbury is a good call to say, as Yvette Cooper has said, let's have a good look at this again and see whether there is some pattern here of people who go out jogging and fall dead, and who are found dead in their house in Surrey, and so on.
"There has got to be something here that at least is worth looking at."
It appeared he was referring to the deaths of two Russian exiles - banker Alexander Perepilichnyy, 44, who collapsed while jogging near his home in Weybridge, Surrey, in November 2012, and oligarch Boris Berezovsky, 67, who was found dead in a Sunninghill, Berkshire, home in March 2013.
An inquest into Perepilichnyy's death is due to resume in mid-April, is looking at whether he died from natural causes or was poisoned.
The dad-of-two was allegedly helping specialist investment firm Hermitage Capital Management uncover a $230 million (£150 million) Russian money-laundering operation at the time of his death.
Mr Berezovsky, who was living in exile in the UK after falling out with Putin, died under mysterious circumstances.
The former Kremlin insider's body was found slumped at his ex-wife's luxury home, with a ligature wound to his neck.
A piece of the same material around his throat was tied on to the shower rail above him, indicating he apparently hanged from the rail.
Police told a coroner they could not rule out murder, and an open verdict was returned at an inquest in March 2014.
Coroner Peter Bedford said he could not prove beyond all reasonable doubt that Mr Berezovsky took his own life or was unlawfully killed.
The attempted murder of the Skripals has drawn comparisons to the poisoning of Russian dissident Alexander Litvinenko.
The 43-year-old died weeks after drinking tea laced with radioactive polonium-210 at London's Millennium Hotel in 2016.
A public inquiry concluded that the killing of the outspoken critic of Putin had "probably" been approved by the Russian president.
Russia denied any involvement in the dissident's death and refused two extradite two Russian agents suspected in the case.
Mr Skripal was a former Russian military intelligence colonel who became an MI6 informant and betrayed dozens of Russian agents.
He was arrested in Moscow in 2004 and sentenced to 13 years in prison in 2006.
In 2010, he was granted refuge in the UK, where he settled in Salisbury, after he was pardoned by Russia and exchanged in a Cold-War spy swap between Moscow and Washington.
Foreign Secretary Boris Johnson has welcomed international support over the poisoning as the deadline for Russia to provide a "convincing explanation" creeps closer.
France, Germany and US Secretary of State Rex Tillerson all gave their backing to the UK.