In the meantime, British police confirmed the death of a man "in his 60s" who lived in Clarence Avenue, New Malden, which was Glushkov's London residential address. In the meantime, Glushkov was charged with money laundering and fraud, ending up behind bars for five years in Russian Federation.
Britain granted Glushkov political asylum, reportedly in 2010, after he had been sentenced in Russian Federation for allegedly embezzling millions from Aeroflot.
He, however, lost Putin's favor and fled to London, where he often criticized the Russian government.
Scotland Yard said anti-terror police were investigating his death "as a precaution because of associations that the man is believed to have had".
He later said he was told at the time that he would be killed on his way to court, saying: "I was told the way it would happen".
Glushkov was a close associate of Russian oligarch Boris Berezovsky.
In 2013, Berezovsky was found dead in his home in the United Kingdom, apparently after committing suicide.
Authorities said the two are believed to have been poisoned by Novichok, a nerve agent believed to be 5 to 8 times more potent than VX or sarin. Too many bodies are happening.
He was thought to have been single, he had two grown-up children, Natasha - believed to live in the United Kingdom - and Dima, and an ex-wife in Moscow.
The report comes after British Prime Minister Theresa May said it's "highly likely" Russia was responsible for the poisoning of ex-Russian spy Sergei Skripal and his daughter in the United Kingdom earlier this month.
Glushkov was due to appear at a United Kingdom court in a case where Aeroflot claimed he stole $123 million from them.
Russian media said he was granted political asylum in Britain in 2010.
Separately, OPCW Director-General Ahmet Uzumcu said: "It is extremely worrying that chemical agents are still being used to harm people".
As the fallout from the Skripal poisoning continued, Britain's media regulator, Ofcom, announced that Kremlin-backed news channel RT could lose its license to broadcast in the UK.
Russian Federation on Tuesday dismissed accusations of any involvement in the poisoning of the ex-spy and his daughter as "nonsense, " saying it will only cooperate with a British investigation if it receives samples of the nerve agent believed to have been used.