The Metropolitan police also said that "the death is now being treated as an unexplained", while "there is no evidence to suggest a link to the incident in Salisbury".
There is no evidence to suggest a link to the March 4 poisoning of former spy Sergei Skripal and his daughter, the statement said.
"At this stage the Met Police Counter Terrorism Command is leading the investigation as a precaution because of associations that the man is believed to have had".
Nikolai Glushkov, 68, was discovered dead late on Monday at an address in Clarence Avenue in suburban south-west London.
Mr Glushkov's friend Damian Kudryavtsev posted a tribute on his Facebook page, with a photo of of Mr Glushkov and the simple message: "Nikolai Glushkov 1949-2018". Police confirmed that "a man in his 60s" was found dead but did not name Glushkov directly. His family has been informed and a post-mortem examination will be held in due course.
In 2000, he was arrested in connection with the embezzlement of Aeroflot's funds, and later charged with fraud and money laundering.
The victim is believed to be Nikolai Glushkov, who claimed political asylum in the United Kingdom after being convicted of fraud, the BBC reports.
Glushkov said: "You have the deaths of Boris and Badri over a short period of time".
Glushkov, who has been an executive at state airline Aeroflot and also worked for Berezovsky's auto company LogoVAZ, followed and was granted asylum in 2010.
Mr Berezovsky was himself found dead on a bathroom floor at his home in southern England in 2013 with a scarf around his neck. His death was not treated as suspicious, but his friends were not convinced and a coroner later recorded an open verdict.
Glushkov is believed to have two grown up children, Natasha and Dima, and an ex-wife who lives in Moscow.