The body of the 68-year-old was discovered at his south London home on March 23, just hours after Theresa May issued an ultimatum in the House of Commons to Vladimir Putin over the poisoning of Russian spy Sergei Skripal and his daughter in Salisbury.
A post-mortem examination on Friday indicated Mr Glushkov was strangled to death and counterterrorism detectives are now treating his death as murder.
Police have now reassessed their previous view that other Russian exiles are at low risk of being harmed, and are contacting them, according to the BBC.
Although police say there is currently no link to the attempted murders of Mr Skripal and his daughter Yulia, the Metropolitan Police said the force’s Counter Terrorism Command would continue to lead the Glushkov’s murder investigation “because to the associations Mr Glushkov is believed to have had”.
And detectives are supposedly remaining open-minded and urges anyone who may have information which could assist the investigation to come forward.
They are appealing for anyone who may have heard or seen anything suspicious at or near his home in Clarence Avenue, New Malden between Sunday 11 March and Monday 12 March to get in touch.
Mr Glushkov, a former deputy director of Russian state airline Aeroflot was jailed in Russia in 1999 for five years after being charged with fraud and money laundering.
After receiving another suspended sentence for fraud in 2006, Mr Glushkov was granted political asylum in the UK when he fled Moscow.
He was set to appear in a London court just this week, and was being sued by Russian authorities for over £99 million of Aeroflot’s money.
Aeroflot alleged that he and Boris Berezovsky, a former Russian business oligarch, embezzled the money.
Alex Goldfarb, a vocal opponent of Mr Putin, who knew Mr Glushkov for several years, said: “I think he was murdered by the Russians. I do not think anything of that sort could happen without Putin’s knowledge. It is obvious to me that it comes from the Kremlin.”
He added: “All of it looks like a campaign to target Britain, which has annoyed Putin for many years and to intimidate others who might be thinking of fleeing: there is no protection.”
Mr Glushkov was also close to Mr Berezovsky, who was found dead in his former wife’s Berkshire home in 2013. Both men were vocal critics of President Vladimir Putin.
Mr Glushkov was said to have convinced that Mr Berezovsky and other exiles had been victims of murder.
Lord Bell, former PR ad advertising executive, who was also close to Mr Glushkov expressed his concern over his friend’s history which he said may have made Russia believe he worked against the state.
Other friends of Mr Glushkov say that he was was at the top of a list published by the Russian embassy in London a year ago which contained the names of 22 so-called fugitives.
The UK is set to expel 23 Russian diplomats as part of a “full and robust” response to the poisoning of Mr Skripal and his daughter – a move which has led to Russia’s decision to expel 23 British diplomats from the country within a week.