A close associate of an outspoken critic of Russian leader Vladimir Putin has been found dead in his London home.
Nikolai Glushkov, 69, once worked for a company owned by Russian oligarch Boris Berezovsky. Berezovsky built a business empire valued in the billions before running afoul of the Kremlin and publicly denouncing Putin.
Glushkov’s cause of death was not immediately known.
Glushkov also once testified in court against billionaire Roman Abramovich, a Putin ally who is also the owner of the Chelsea Football Club.
In the 1990s, Glushkov held a senior position with Russian airline Aeroflot.
Berezovsky was a close associate of Alexander Litvinenko, a former spy who was killed with a radioactive poison in London in 2006. A British inquiry concluded that Litvinenko’s death was the work of the Russian state and had probably been authorized by Putin.
Glushkov’s death was confirmed by Damian Kudryavtsev, a board member of the Moscow Times, in a Facebook post Tuesday. Kudryavtsev was close with both Berezovsky and Glushkov.
London’s Metropolitan Police said Glushkov’s death was “currently being treated as an unexplained.” However, counterterrorism officers were leading the investigation “as a precaution because of associations that the man is believed to have had.”
Berezovsky sold his holdings in Russia and sought refuge in London following a fraud investigation into his management and Glushkov’s management of Aeroflot.
Berezovsky, who later suffered serious financial problems, was found dead in a locked bathroom in his home in 2013. He had a rope around his neck and it was believed at the time that he took his own life.
In an interview with The Guardian after Berezovsky’s death, Glushkov said: “Boris was strangled. Either he did it himself or with the help of someone. [But] I don’t believe it was suicide.”
Meanwhile, Britain’s government announced that police and security services will open new investigations into more than a dozen deaths reportedly linked to Russian security services and mafia groups.
Confirmation that the deaths will be looked at again comes days after a Russian ex-spy and his daughter were found poisoned in the English city of Salisbury last week.
U.K. Prime Minister Theresa May said it was “highly likely” the Russian government was responsible for the attack targeting double agent Sergei Skripal. She has given Putin until midnight Tuesday (8 p.m. ET) to come up with an explanation.
Following the incident in Salisbury last week, Yvette Cooper, an opposition lawmaker and chair of the Home Affairs Committee, wrote to Home Secretary Amber Rudd and asked her to look into 14 other deaths highlighted in an investigation by BuzzFeed last year.
Citing U.S. intelligence sources, BuzzFeed reported that these people were suspected of being assassinated on British soil by Russian security services or mafia groups, “two forces that sometimes work in tandem.”
The evidence, Cooper said, “raises serious doubts about the decisions made in each case to treat them either as suicides, natural causes or accidents.” She added that the evidence “raises questions over the robustness of the police investigations.”
Rudd’s response was published Tuesday.
“I will want to satisfy myself that the allegations are nothing more than that,” she said. “The police and MI5 [Britain’s domestic intelligence agency] agree and will assist in that endeavor.”