United Kingdom counter-terror police are investigating the "unexplained death" of a Russian businessman in London.
Nikolai Glushkov, 68, was discovered dead late on Monday at an address in Clarence Avenue in suburban south-west London.
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".
It added that there was "no evidence to suggest a link to the incident in Salisbury". In 1999, Glushkov was charged with money laundering and fraud after Berezovsky fell out with Russian President Vladimir Putin and fled to Britain.
"Whilst we believe we know the identity of the deceased, formal identification is yet to take place", police said in a statement. A post-mortem examination will be held in due course.
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His cause of death is now unclear. "If there is a change in the status of the investigation, an update will be provided", the Met said.
Glushkov, who worked for Berezovsky's LogoVAZ vehicle company, was charged with money laundering and fraud and spent five years in jail from 1999.
Glushkov worked in the 1990s for the state airline Aeroflot and Berezovsky's LogoVAZ auto company, according to media reports.
He was found dead on Monday night.
Police said he killed himself, but his friends were less certain and a coroner recorded an open verdict.
Glushkov had said at the time that he did not believe Berezovsky died of natural causes. Natasha is believed to live in the UK. In March 2017, Moscow's Savelovsky District Court handed him a second eight-year sentence in absentia for the embezzlement of Aeroflot's funds.