LONDON: An investigation into the sudden death of a Russian supergrass in Britain is being reviewed by specialist detectives amid mounting concern that he might have been murdered.
Alexander Perepilichnyy, 44, who moved to Britain three years ago after falling out with a Moscow crime syndicate, was found dead outside his large home on a private estate near Weybridge last month. His death has been described as "unexplained" and Surrey police initially said it was not being treated as suspicious.
But after it emerged that Mr Perepilichnyy was co-operating with the Swiss authorities in a major corruption investigation linked to a string of other deaths, police chiefs ordered that the case be passed to the force's Major Crimes Unit.
Police sources said the unit, which investigates complex murder cases, would be taking a fresh look at the circumstances of Mr Perepilichnyy's death.
Detectives will speak to his friends and business associates in a renewed effort to establish how a 44-year-old man, who was apparently in good health, came to collapse suddenly and die.
One theory is that he could have been poisoned in a similar fashion to Alexander Litvinenko, the former KGB agent who died in London in 2006 after being contaminated with radioactive Polonium 210.
Detectives are awaiting the results of toxicology tests.
Mr Perepilichnyy sought sanctuary in Britain in 2009 after agreeing to expose a sophisticated network of corrupt Moscow businessmen suspected of involvement in a large tax fraud. The network, which was allegedly tied up with the Klyuev organised crime syndicate, was thought to be behind a scam which had cost the British-based company Hermitage Capital Management millions of pounds.
The chief executive of Hermitage, Bill Browder, has accused Surrey Police of being slow off the mark in recognising the complexity of the case. He said his lawyers had written to the force several times to urge it to carry out a specialist post-mortem examination "but were brushed off entirely". He said it was only when media reports surfaced last week that the force passed the case to murder detectives in the Major Crimes Unit.
A spokesman for Surrey Police said: "The investigation has always been ongoing. The Major Crimes Unit is now examining the circumstances of Mr Perepilichnyy's death which is being treated as unexplained."
Hermitage was one of the largest foreign investors in Russia until becoming the victim of a £144 million ($221 million) tax fraud scheme in 2007.
Sergei Magnitsky, a Moscow-based lawyer hired by Hermitage to investigate the claims, concluded that Russian tax officials had been laundering millions of pounds through Swiss bank accounts.
But after going public with his claims and testifying against several senior police officers, Mr Magnitsky was arrested and placed in prison. The 37 year-old was held for more than a year without trial and was eventually found dead in his prison cell after allegedly being beaten and tortured.
Two other men believed to be embroiled in the scandal, Octai Gasanov and Valery Kurochkin, were also found dead in mysterious circumstances.
The investigation into the alleged money laundering had been faltering until Mr Perepilichnyy handed over a cache of documents to Swiss prosecutors. His associates believe his death could be linked with the case and are urging the police to ensure all aspects of his life in Russia and Britain are closely examined.