A video has re-emerged online that shows Vladimir Putin issuing apparent death threats to Russia’s “traitors”.
The footage from 2010 was shared widely hours after a retired double agent, Sergei Skripal, was allegedly poisoned in Salisbury.
In the clip the Russian President is seen warning that those who betray the country would face consequences.
“Traitors will kick the bucket, believe me. Those other folks betrayed their friends, their brother in arms,” Mr Putin said.
“Whatever they got in exchange for it, those 30 pieces of silver they were given, they will choke on them.”
Mr Skripal, who was given refuge in the UK after being jailed in his home country for treason, was found unconscious on a bench alongside his daughter, Yulia, in a local shopping centre.
The exact cause of their illness has not yet been confirmed but it is believed they were exposed to an unknown substance.
Several members of emergency services personnel who responded to the call were themselves taken ill, with one requiring hospital treatment.
The case drew immediate comparison to the murder of former FSB officer Alexander Litvinenko using radioactive polonium-210 believed to have been administered in a cup of tea.
Investigators are understood to be reviewing the death of Mr Litvinenko to see if there are any similarities between the modus operandi of that case and this incident.
Mr Putin’s words will not come as a surprise to Victor Makarov, a former KGB agent who also turned and spied for Britain and was once a colleague of Mr Skripal.
Like Mr Skripal, Mr Makarov defected to the UK after serving as a double agent and in 2007 from his house in northern England, Mr Makarov spoke of his fears that the KGB would seek revenge.
"They will try to shoot me in the back of the head, but they might use poison," he said.
"They never forget. When I was at the KGB in the 1970s they were still chasing people who had betrayed them 30 years before."
The Russian government has denied any involvement in Mr Skripal's apparent poisoning, and said his illness was being used in the UK as part of an "anti-Russia campaign".