A British coroner on Thursday opened an inquest to establish the cause of death of Russian exile Nikolai Glushkov, who was found at his London home on March 12.
The inquest at West London Coroner's Court was told that a post-mortem discovered the 68-year-old businessman suffered from compression to the neck, suggesting he may have been strangled.
His family said Wednesday they were "devastated" by the death.
"We are devastated at the loss of Nikolai and are coming to terms with our grief," they said in a statement.
Scotland Yard opened a murder probe last week following the autopsy results.
Glushkov had received political asylum in Britain after being jailed in Russia for money laundering and fraud.
He was linked to late Kremlin opponent Boris Berezovsky, an oligarch and one-time supporter of Russian President Vladimir Putin, who was found hanged in his home outside London in 2013.
The Russian embassy in London said that it had asked British authorities for details of Glushkov's death.
The suspected murder is not believed to be linked to the nerve agent attack on former double agent Sergei Skripal and his daughter Yulia in Salisbury, southwest England, on March 4, which has caused a diplomatic row between the two countries.
In English law, inquests are held to examine violent, unnatural or unexplained deaths. They set out to determine the place and time of death as well as how the deceased came by their death, but do not apportion blame.
The inquest was adjourned.