By Maria Golovnina
LONDON, Dec 3 (Reuters) - A British serious crime unit has taken over an investigation into the mysterious death of a Russian anti-corruption whistleblower, police said on Monday, in a move local media said suggested it might have been a murder.
Alexander Perepilichny, 44, moved to Britain three years ago and had been helping Swiss prosecutors investigate a Russian criminal group suspected of being involved in major tax fraud.
He collapsed and died near his home on an upmarket private estate in southeast England on Nov. 10. Police have not been able to explain why he died, even after two autopsies, and have ordered toxicology tests on the body.
On Monday, police said the investigation had been handed over by local police to a team of specialist detectives working for a regional major crimes team.
"It's an unexplained death," said a local police spokesman. "They are waiting for the toxicology report which will take a number of weeks. ... (It) will be the next major milestone in the case."
Asked if detectives were treating the case as a possible murder, the spokesman said: "At the moment the death is unexplained, so they are still keeping their mind (open) and following up on a number of lines of inquiry".
SPOTLIGHT ON CRIMINAL GROUPS
One theory being explored, the Guardian newspaper reported, is that he could have been poisoned in a similar fashion to former spy Alexander Litvinenko, who died in London in 2006 after drinking tea laced with radioactive polonium-210.
The Daily Telegraph newspaper also reported there were "concerns that he could have been murdered".
Perepilichny's unexplained death has shone a new spotlight on Russian criminal groups working in Europe. Since moving to Britain, he had been providing information to Swiss prosecutors to help them expose people involved in a Russian tax fraud.
The existence of the tax fraud syndicate originally came to light as part of an earlier investigation by Russian lawyer Sergei Magnitsky, who was jailed in 2008 by the Russian authorities on charges his colleagues say were fabricated.
Magnitsky himself died in a Russian jail in 2009, becoming a symbol of rights abuse and corruption. Russian officials have denied any link between Magnitsky and Perepilichny.
Perepilichny appeared to be in good health when he died, apparently while out jogging near his mansion.
Locals at the estate - dubbed Britain's Beverly Hills and ringed by neatly trimmed golf courses and security check points - told Reuters last week the Russian was wearing running clothes when his body was discovered at the top of a hill.
After moving to Britain, he acted as a witness in a Swiss investigation of the Russian criminal group which allegedly laundered proceeds from tax fraud operations through Swiss bank accounts to buy luxury property outside Russia.
Britain's Independent newspaper, financially backed by a Russian businessman critical of the Kremlin, reported last week that Perepilichny received a warning a year ago that his name was on a hit list in Russia.