Nikolay Glushkov, a friend of a Vladimir Putin critic who was found dead with a rope around his neck, was strangled, police said.
British police launched a murder investigation Friday after an autopsy revealed that a Russian exile who was critical of Vladimir Putin was strangled in his home.
Nikolay Glushkov, whosebody was found Monday, died as a result of "compression to the neck," London's Metropolitan Police said in a statement.
Glushkov's death was a eerie echo of his friend Boris Berezovsky, an exiled Russian oligarch and an outspoken critic of Putin who was found in 2013 with a rope around his neck — and whose death was initially a suspected suicide. It was reclassified as unexplained.
"Boris was strangled," Glushkov said afterward in an interview withThe Guardian newspaper. "Either he did it himself or with the help of someone. [But] I don't believe it was suicide."
So far, police said, there is no link between the death of Glushkov and "the attempted murders in Salisbury, nor any evidence that he was poisoned."
That was a reference to the attempted assassinations of former Russian double agent Sergei Skripal and his daughter Yulia, who were found unconscious last weekend on a bench in the city of Salisbury — and who police later said were poisoned with a nerve agent.
They remain in crucial condition and British Prime Minister Theresa May has said it was "highly likely" they were the victims of an attempted hit by Russian military intelligence.
The Russian ambassador in London insisted the British were keeping diplomats in the dark about Glushkov's murder.
"The embassy has no information about the launch of the probe into Glushkov's murder," Alexander Yakovenko said. "The British side is not responding to the embassy's inquiry. It is unacceptable and we consider this situation as a failure of the U.K.'s international liabilities under the Vienna convention of consular access."
Glushkov also once testified in court against the billionaire Roman Abramovich, a Putin ally who owns the Chelsea Football Club, an English soccer team.
Berezovsky was a close friend of former Russian spy Alexander Litvinenko, who died from radioactive poisoning in 2006. An inquiry by British investigators concluded that his death was the work of the Russian state and was probably green-lighted by Putin himself.
Following the poisonings of the Skripals, Yvette Cooper, a British lawmaker, 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 the deceased were suspected of being assassinated on British soil by Russian security services or mafia groups, "two forces that sometimes work in tandem."