The Russian Embassy has revealed it learned about the suspected murder of one of its citizens in Britain through the media, as an inquest opened into the businessman's death.
The country's ambassador to London claimed officials had been deliberately ignored by Britain after requesting information on the circumstances of how Nikolay Glushkov died.
Alexander Yakovenko said the Foreign Office in the UK failed to provide "any meaningful response" so far following the embassy's request under the Vienna Convention.
During a press conference in London he criticised Britain for its blame of Russia in the Salisbury spy poisoning case and highlighted the death of Mr Glushkov.
He said: "It seems that the British side is deliberately ignoring our requests and continues to avoid any contacts with the Embassy on this matter."
Mr Glushkov was found dead in his home on Clarence Avenue, New Malden, on March 12 but four days later the Met launched a murder investigation.
An inquest which was opened and adjourned at West London Coroner's Court on Thursday heard the 68-year-old's cause of death was compression to the neck, and that he was pronounced dead at 10.48pm.
Mr Glushkov fled Russia after being accused of fraud during his time as deputy director of the Russian airline Aeroflot.
Last year, during a trial in absentia he was sentenced to eight years in a Russian prison, convicted of stealing £87 million from the airline.
He was due to attend the commercial court in London to defend himself on Monday March 12 - the day his body was discovered.
Mr Glushkov was a close friend of Putin critic Boris Berezovsky.
The oligarch was found hanged at his Berkshire home in 2013 but an inquest into his death recorded an open verdict.
On Wednesday Mr Glushkov's family released a statement saying they were devastated at his death.
The inquest was adjourned for a date to be fixed.