A murder investigation has been launched into the death of Russian businessman Nikolai Glushkov following the results of a postmortem exam, British police said in a statement on Friday.
The Russian exile, who had links to compatriots who died in mysterious circumstances in the UK, was found dead in his London home Monday evening.
According to the police statement, the examination "gave the cause of death as compression to the neck."
The statement also said the Metropolitan Police Counter Terrorism Command "is retaining primacy for the investigation because of the associations Mr. Glushkov is believed to have had."
Glushkov's death came just over a week after the poisoning of former Russian spy Sergei Skripal and his daughter Yulia in the English city of Salisbury on March 4.
Police said there is no evidence that the incidents are linked at this stage.
There is "nothing to suggest any link to the attempted murders in Salisbury, nor any evidence that he was poisoned," the statement said.
Earlier on Friday, the Russian Investigative Committee also launched criminal proceedings into what it calls the "murder" of Glushkov.
"Investigators are ready to work together with competent authorities in Great Britain," the committee said in a statement.
Associations with oligarchs
Glushkov was found dead at his home in New Malden, southwest London, Monday evening. Police were called by ambulance services at 10.46 p.m. local time to the address in the borough of Kingston.
Forensic crews attended the scene and police removed several bags of evidence, according to neighbor Pat Egan.
Glushkov was a friend and former employee of Boris Berezovsky, a powerful oligarch found dead in his UK home in 2013. Glushkov was never convinced by the police explanation that Berezovsky killed himself.
He was granted political asylum in the UK in 2010, and in February 2016 Britain refused a request from Russia to extradite him on fraud charges connected to a period in the 1990s when he was deputy director of the Russian national airline Aeroflot.
In 2000, Glushkov was arrested on charges of embezzling funds from Aeroflot, in which Berezovsky was a shareholder.
He was sentenced by a Moscow court in 2004 to three years and three months in prison and released for time served, Russian news agency Tass reported.
After arriving in the UK as a political refugee, Russian courts continued to pursue him. Last year, a Moscow court tried him in absentia for embezzlement from Aeroflot.
Acquaintances in London
Glushkov was also questioned as part of a British inquiry into the death of former Russian spy Alexander Litvinenko, who was poisoned with highly radioactive polonium-210 in 2006 in a hotel bar in London. Glushkov told the inquiry that he bumped into Litvinenko in Berezovsky's office.
Berezovsky was found dead in 2013 on the bathroom floor of his home in Berkshire, west of London. British police said at the time they found no sign of a struggle, suggesting Berezovsky had taken his own life. Glushkov argued publicly that he believed the exiled tycoon had been murdered.