The news that a former Russian spy is in hospital amid mysterious circumstances has prompted comparisons with the death of Alexander Litvinenko - including from his widow.
A Russian dissident who became a British citizen, Litvinenko died aged 43 in November 2006, three weeks after he drank tea laced with radioactive polonium-210 at the Millennium Hotel in Mayfair, central London.
A public inquiry concluded in 2016 that the killing of Litvinenko, an outspoken critic of Vladimir Putin, had "probably" been carried out with the approval of the Russian president.
As Sergei Skripal, 66, fought for his life after being found unconscious on a bench in Salisbury, Marina Litvinenko told BBC Radio 4's World Tonight: "It's like deja vu, (like) what happened to me 11 years ago."
"In Russia it is still (an) old-fashioned and old-style KGB system... It's still all the same. If there is an order to kill somebody it will happen," she said.
Police have said they are as yet "unable to ascertain" whether Skripal had been a victim of crime, while the a Russian Embassy spokesman said: "Neither relatives nor legal representatives of the said person, nor the British authorities have addressed the embassy in this regard."
The Litvinenko inquiry, headed by the former high court judge Sir Robert Owen, found two Russian men - Andrei Lugovoi and Dmitri Kovtun - had deliberately poisoned their victim, leading to an agonising death.
It said the use of the radioactive substance - which could only have come from a nuclear reactor - was a "strong indicator" of state involvement and that the two men had probably been acting under the direction of the FSB, Russia's state agency.
Possible motives included Litvinenko's work for British intelligence agencies, his criticism of the FSB, and his association with other Russian dissidents, while it said there was also a "personal dimension" to the antagonism between him and Putin.
International arrest warrants issued for Lugovoi and Kovtun remain in force although Russia continues to refuse their extradition.
Putin had refused to accept the inquiry's findings.
Australian Associated Press