The death of a prominent Kremlin critic on British soil is now being treated as murder, Scotland Yard has announced.
Russian exile Nikolay Glushkov, 68, was found dead at his home in Clarence Avenue, south-west London, on Monday.
The Metropolitan Police were called to the scene at 10.46 pm and initially said the death was being treated as unexplained.
But a post-mortem investigation, which began on Thursday, concluded he was killed by compression to the neck, the force said on Friday.
It comes after the attempted murder by poisoning of former Russian double agent Sergei Skripal and his daughter barely a week earlier, but detectives said yesterday there was nothing to link the two attacks.
There was also no evidence that the businessman was poisoned, the force said, and there are no public health concerns.
A murder investigation has been launched, led by the counter-terrorism command, who will retain primacy “because of the associations Mr Glushkov is believed to have had”, the Met said.
Mr Glushkov was outspoken after the death of his close friend Boris Berezovsky – another enemy of Russian President Vladimir Putin.
Mr Berezovsky had been a friend of Alexander Litvinenko, a Russian spy who fled to the UK and was later killed with a radioactive chemical while in London.
Mr Berezovsky himself was found hanged in the bathroom of his Berkshire home in 2013.
An inquest recorded an open verdict.
Mr Glushkov told the Guardian in 2013 he would “never believe” he took his own life.
He was a retired financial director who had lived at his address for two years, Scotland Yard said on Friday.
Detectives are appealing in particular for anyone who may have seen or heard anything suspicious at or near his home in Clarence Avenue between Sunday March 11 and Monday March 12 to contact them.